如何使用jquery或javascript删除textarea中以＃开头的所有字符？

Question

I have the code below

<textarea id="description" name="description" rows="10" placeholder="Description..." class="valid"> 
This is an example text i wanna keep. 
# And i want to remove all this content.
</textarea>

how can i remove only this text from the textarea

# And i want to remove all this content.

using jquery or javascript ?

As you can see i want all the content that start with a hashtag to be removed.

Answer 1

Only for textarea, you may use a simple Regular Expression, with "m" (multiline) flag.

• Where $ means end of the line;
• special . matches with any symbol,
• * means 'match from zero to infinite times'

 let desc = document.getElementById('description'); desc.value = desc.value.replace(/#.*$/gm,""); 

 textarea {width: 80%;} 

 <textarea class="js-replace" id="description" name="description" rows="10" placeholder="Description..."> This is an example text i wanna keep. # And i want to remove all this content. Bubu and replace #Me But not me! </textarea> 

Version for multiple elements, textarea, div, etc - replace by className:

 let replace = document.querySelectorAll('.js-replace') for( let i = 0; i < replace.length; i++ ){ let area = /TEXTAREA|INPUT/.test(replace[i].tagName); // will return true or false; let content = area ? "value" : "innerHTML"; // Ternary operator. (condition) ? (value if true) : (value otherwise) // replace[i]['value'] if textarea and replace[i]['innerHTML'] if other element replace[i][content] = replace[i][content].replace(/#.*?(\\n|<br>|$)/g, "$1"); // (*1) } 

 textarea {width: 80%;} 

 <textarea class="js-replace" id="description" name="description" rows="10" placeholder="Description..."> This is an example text i wanna keep. # And i want to remove all this content. Bubu and replace #Me But not me! </textarea> <div class="js-replace"> This is an example text i wanna keep. <br># And i want to remove all this content. <br> <br>Bubu and replace #Me <br>But not me! </div> 

(*1): .replace(/#.*?(\\n|<br>)/g, "$1") — string, starting from # symbol, matching .* anything (instead of line-break \\n ), many times, and ? stop as soon as it faces with \\n line break | or <br> HTML-line break. "$1" — equals to match in the first (parentheses). Ie we replace all string, but keep line-break.

But this will not work correctly, if you want to delete, for example, comments from Python... because you may delete strings with "str... # str"