String processing in JavaScript is a basic skill that any developer needs to know, similar to array, String is constantly improving and updating by developers. Up to now, there must also be 9,000 8 thousand different methods of processing chains to contribute to making developers more brain pain when using. Let’s learn about popular methods with me through this article!
1. String.prototype.charAt ()
- Returns the character in the position specified by the index. For example the first position is 0 followed by 1, 2 …
- If index is out of range, an empty string is returned
1 2 3 4 5 6 | <span class="token keyword">const</span> sentence <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog.'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> index <span class="token operator">=</span> <span class="token number">4</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> index1 <span class="token operator">=</span> <span class="token number">100</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The character at index </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> index <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charAt</span> <span class="token punctuation">(</span> index <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The character at index 4 is q"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The character at index </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> index1 <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charAt</span> <span class="token punctuation">(</span> index1 <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The character at index 100 is "</span> |
Syntax
1 2 3 4 5 | str <span class="token punctuation">.</span> <span class="token function">charAt</span> <span class="token punctuation">(</span> index <span class="token punctuation">)</span> <span class="token comment">/* index: số nguyên trong khoảng 0 tới str.length - 1 nếu index không thể chuyển đổi sang số nguyên hoặc index không được cung cấp thì mặc định index = 0 */</span> |
2. String.prototype.charCodeAt ()
- Returns an integer between
0
and65535
accordance with the UTF-16 standard - If index is out of range,
NaN
returned
1 2 3 4 5 6 | <span class="token keyword">const</span> sentence <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog.'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> index <span class="token operator">=</span> <span class="token number">4</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> index1 <span class="token operator">=</span> <span class="token number">100</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The character code </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charCodeAt</span> <span class="token punctuation">(</span> index <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> is equal to </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charAt</span> <span class="token punctuation">(</span> index <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The character code 113 is equal to q"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The character code </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charCodeAt</span> <span class="token punctuation">(</span> index1 <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> is equal to </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">charAt</span> <span class="token punctuation">(</span> index1 <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The character code NaN is equal to "</span> |
Syntax
1 2 3 4 5 | str <span class="token punctuation">.</span> <span class="token function">charCodeAt</span> <span class="token punctuation">(</span> index <span class="token punctuation">)</span> <span class="token comment">/* index: số nguyên trong khoảng 0 tới str.length - 1 nếu index không phải là số thì mặc định index = 0 */</span> |
3. String.prototype.concat ()
Usually to concatenate strings we often use the +
sign, however JS provides us with this method with similar functionality
- This method returns a new string after concatenation
1 2 3 4 5 | <span class="token keyword">const</span> str1 <span class="token operator">=</span> <span class="token string">'Hello'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> str2 <span class="token operator">=</span> <span class="token string">'World'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> str3 <span class="token operator">=</span> <span class="token string">'!'</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> str1 <span class="token punctuation">.</span> <span class="token function">concat</span> <span class="token punctuation">(</span> <span class="token string">' '</span> <span class="token punctuation">,</span> str2 <span class="token punctuation">,</span> <span class="token string">' '</span> <span class="token punctuation">,</span> str3 <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "Hello World !"</span> |
Syntax
1 2 3 4 | str <span class="token punctuation">.</span> <span class="token function">concat</span> <span class="token punctuation">(</span> str2 <span class="token punctuation">[</span> <span class="token punctuation">,</span> <span class="token operator">...</span> strN <span class="token punctuation">]</span> <span class="token punctuation">)</span> <span class="token comment">// str2 [, ...strN]: các chuỗi sẽ nối tiếp vào str</span> |
4. String.prototype.includes ()
- Used to check whether a string can be found in another string
- Returns
true
if found, orfalse
otherwise
1 2 3 4 5 6 | <span class="token keyword">const</span> sentence <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog.'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> word <span class="token operator">=</span> <span class="token string">'fox'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> word1 <span class="token operator">=</span> <span class="token string">'hello'</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The word '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> word <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">includes</span> <span class="token punctuation">(</span> word <span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token string">'is'</span> <span class="token operator">:</span> <span class="token string">'is NOT'</span> <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> in the sentence</span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The word 'fox' is in the sentence"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The word '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> word1 <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> sentence <span class="token punctuation">.</span> <span class="token function">includes</span> <span class="token punctuation">(</span> word1 <span class="token punctuation">)</span> <span class="token operator">?</span> <span class="token string">'is'</span> <span class="token operator">:</span> <span class="token string">'is NOT'</span> <span class="token interpolation-punctuation punctuation">}</span></span><span class="token string"> in the sentence</span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The word 'hello' is NOT in the sentence"</span> |
Syntax
1 2 3 4 5 | str <span class="token punctuation">.</span> <span class="token function">includes</span> <span class="token punctuation">(</span> searchString <span class="token punctuation">[</span> <span class="token punctuation">,</span> position <span class="token punctuation">]</span> <span class="token punctuation">)</span> <span class="token comment">// searchString: từ khóa để tìm kiếm bên trong str</span> <span class="token comment">// position (không bắt buộc): Vị trí trong chuỗi bắt đầu tìm kiếm cho searchString (mặc định là 0)</span> |
5. String.prototype.indexOf ()
- Used to find the position of a string in another string
- Returns the first position found (starting from the position specified to be searched) or
-1
if not found
1 2 3 4 5 6 7 8 | <span class="token keyword">const</span> paragraph <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog. If the dog barked, was it really lazy?'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> searchTerm <span class="token operator">=</span> <span class="token string">'dog'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> indexOfFirst <span class="token operator">=</span> paragraph <span class="token punctuation">.</span> <span class="token function">indexOf</span> <span class="token punctuation">(</span> searchTerm <span class="token punctuation">)</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The index of the first '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> searchTerm <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' from the beginning is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> indexOfFirst <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The index of the first 'dog' from the beginning is 40"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The index of the 2nd '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> searchTerm <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> paragraph <span class="token punctuation">.</span> <span class="token function">indexOf</span> <span class="token punctuation">(</span> searchTerm <span class="token punctuation">,</span> <span class="token punctuation">(</span> indexOfFirst <span class="token operator">+</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The index of the 2nd 'dog' is 52"</span> |
Syntax
1 2 3 4 5 | str <span class="token punctuation">.</span> <span class="token function">indexOf</span> <span class="token punctuation">(</span> searchValue <span class="token punctuation">[</span> <span class="token punctuation">,</span> fromIndex <span class="token punctuation">]</span> <span class="token punctuation">)</span> <span class="token comment">// searchValue: từ khóa để tìm kiếm</span> <span class="token comment">// fromIndex (không bắt buộc): vị trí bắt đầu để tìm kiếm, mặc định là 0</span> |
6. String.prototype.lastIndexOf ()
In contrast to indexOf()
, it starts looking at the end of the string
1 2 3 4 5 6 7 8 | <span class="token keyword">const</span> paragraph <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog. If the dog barked, was it really lazy?'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> searchTerm <span class="token operator">=</span> <span class="token string">'dog'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> indexOfFirst <span class="token operator">=</span> paragraph <span class="token punctuation">.</span> <span class="token function">lastIndexOf</span> <span class="token punctuation">(</span> searchTerm <span class="token punctuation">)</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The index of the first '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> searchTerm <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' from the beginning is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> indexOfFirst <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The index of the first 'dog' from the beginning is 52"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> <span class="token template-string"><span class="token template-punctuation string">`</span> <span class="token string">The index of the 2nd '</span> <span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> searchTerm <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token string">' is </span><span class="token interpolation"><span class="token interpolation-punctuation punctuation">${</span> paragraph <span class="token punctuation">.</span> <span class="token function">lastIndexOf</span> <span class="token punctuation">(</span> searchTerm <span class="token punctuation">,</span> <span class="token punctuation">(</span> indexOfFirst <span class="token operator">-</span> <span class="token number">1</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token interpolation-punctuation punctuation">}</span></span> <span class="token template-punctuation string">`</span></span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The index of the 2nd 'dog' is 40"</span> |
7. String.prototype.match ()
Regex in JS is something very cool and this method is often used when working with Regex
- Returns the result of a string match with a regular expression .
- Returns an array containing matches or
null
if not found
1 2 3 4 5 6 | <span class="token keyword">const</span> paragraph <span class="token operator">=</span> <span class="token string">'The quick 1 brown fox jumps over the lazy dog. It 3 barked.'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> regex <span class="token operator">=</span> <span class="token regex">/[A-Z]|d/g</span> <span class="token punctuation">;</span> <span class="token comment">// tìm các kí tự in hoa hoặc số</span> <span class="token keyword">const</span> found <span class="token operator">=</span> paragraph <span class="token punctuation">.</span> <span class="token function">match</span> <span class="token punctuation">(</span> regex <span class="token punctuation">)</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> found <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > Array ["T", "1", "I", "3"]</span> |
Syntax
1 2 3 4 | str <span class="token punctuation">.</span> <span class="token function">match</span> <span class="token punctuation">(</span> regexp <span class="token punctuation">)</span> <span class="token comment">// regexp: một biểu thức chính quy</span> |
8. String.prototype.replace ()
- This method is used a lot when you want to replace or delete characters in string
- The string to be replaced can be a simple string or a regular expression
1 2 3 4 5 6 7 8 | <span class="token keyword">const</span> p1 <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog. If the DOG reacted, was it really lazy?'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> p2 <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog. If the dog reacted, was it really lazy?'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> regex <span class="token operator">=</span> <span class="token regex">/dog/gi</span> <span class="token punctuation">;</span> <span class="token comment">// tìm tất cả chuỗi 'dog' không phân biệt hoa thường</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> p1 <span class="token punctuation">.</span> <span class="token function">replace</span> <span class="token punctuation">(</span> regex <span class="token punctuation">,</span> <span class="token string">'123'</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The quick brown fox jumps over the lazy 123. If the 123 reacted, was it really lazy?"</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> p2 <span class="token punctuation">.</span> <span class="token function">replace</span> <span class="token punctuation">(</span> <span class="token string">'dog'</span> <span class="token punctuation">,</span> <span class="token string">'456'</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > "The quick brown fox jumps over the lazy 456. If the dog reacted, was it really lazy?"</span> |
Syntax
1 2 3 4 5 6 7 | <span class="token keyword">const</span> newStr <span class="token operator">=</span> str <span class="token punctuation">.</span> <span class="token function">replace</span> <span class="token punctuation">(</span> regexp <span class="token operator">|</span> substr <span class="token punctuation">,</span> newSubstr <span class="token operator">|</span> <span class="token keyword">function</span> <span class="token punctuation">)</span> <span class="token comment">// regexp: 1 biểu thức chính quy</span> <span class="token comment">// substr: chuỗi bị thay thế</span> <span class="token comment">// newSubstr: chuỗi thay thế</span> <span class="token comment">// function: Một hàm được gọi để tạo chuỗi con mới</span> |
9. String.prototype.search ()
- Used to find the position of a string in another string
- Returns the found position or
-1
otherwise - The search pattern can be a string or a regular expression
1 2 3 4 5 6 | <span class="token keyword">const</span> paragraph <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog 123. If the dog barked, was it really lazy?'</span> <span class="token punctuation">;</span> <span class="token keyword">const</span> regex <span class="token operator">=</span> <span class="token regex">/d/g</span> <span class="token punctuation">;</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> paragraph <span class="token punctuation">.</span> <span class="token function">search</span> <span class="token punctuation">(</span> <span class="token string">'dog'</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > 40</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> paragraph <span class="token punctuation">.</span> <span class="token function">search</span> <span class="token punctuation">(</span> regex <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// > 44</span> |
Syntax
1 2 3 4 | str <span class="token punctuation">.</span> <span class="token function">search</span> <span class="token punctuation">(</span> regexp <span class="token punctuation">)</span> <span class="token comment">// regexp: 1 biểu thức chính quy</span> |
10. String.prototype.slice ()
- Used to extract part of the string and return it as a new string without changing the original string
- This method is quite similar to
slice()
in Array that I introduced to you in the previous article
1 2 3 4 5 6 7 8 9 10 11 12 13 14 | <span class="token keyword">const</span> str <span class="token operator">=</span> <span class="token string">'The quick brown fox jumps over the lazy dog.'</span> <span class="token punctuation">;</span> <span class="token comment">//=> index 01234...</span> <span class="token comment">//=> index ...-1 </span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> str <span class="token punctuation">.</span> <span class="token function">slice</span> <span class="token punctuation">(</span> <span class="token number">31</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// lấy từ index = 31 tới str.length</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> str <span class="token punctuation">.</span> <span class="token function">slice</span> <span class="token punctuation">(</span> <span class="token number">4</span> <span class="token punctuation">,</span> <span class="token number">19</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// lấy từ index = 4 tới index = 19</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> str <span class="token punctuation">.</span> <span class="token function">slice</span> <span class="token punctuation">(</span> <span class="token operator">-</span> <span class="token number">4</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// lấy từ index = -4 tới str.length</span> console <span class="token punctuation">.</span> <span class="token function">log</span> <span class="token punctuation">(</span> str <span class="token punctuation">.</span> <span class="token function">slice</span> <span class="token punctuation">(</span> <span class="token operator">-</span> <span class="token number">9</span> <span class="token punctuation">,</span> <span class="token operator">-</span> <span class="token number">5</span> <span class="token punctuation">)</span> <span class="token punctuation">)</span> <span class="token punctuation">;</span> <span class="token comment">// lấy từ index = -9 tới index = -5</span> <span class="token operator">></span> <span class="token string">"the lazy dog."</span> <span class="token operator">></span> <span class="token string">"quick brown fox"</span> <span class="token operator">></span> <span class="token string">"dog."</span> <span class="token operator">></span> <span class="token string">"lazy"</span> |
Syntax
1 2 3 4 5 6 7 8 9 10 11 12 | str <span class="token punctuation">.</span> <span class="token function">slice</span> <span class="token punctuation">(</span> beginIndex <span class="token punctuation">[</span> <span class="token punctuation">,</span> endIndex <span class="token punctuation">]</span> <span class="token punctuation">)</span> <span class="token comment">/* beginIndex: bắt đầu từ 0 + Nếu là số âm sẽ được tính bằng str.length + beginIndex (ví dụ -3 thì beginIndex = str.length - 3 hoặc bạn có thể đánh chỉ số âm giống mình cho dễ hình dung) + Nếu không phải số nguyên sẽ mặc định là 0 + Nếu lớn hơn str.length thì 1 chuỗi rỗng được trả về */</span> <span class="token comment">/* endIndex (Không bắt buộc): giá trị đánh dấu kết thúc trích xuất + Nếu endIndex bị bỏ qua hoặc không được xác định, hoặc lớn hơn str.length, thì slice() sẽ trích xuất đến cuối chuỗi. + Nếu endIndex được chỉ định và startIndex là âm, thì endIndex phải là số âm, nếu không sẽ trả về một chuỗi rỗng (ví dụ slice(-3, 0) sẽ trả về "") */</span> |
Conclusion
The article is quite long, then I temporarily stop here and will continue to present some more methods in the next article.
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