在 Vanilla Javascript 中自动结束 html 标签

Question

The user enters a tag (like <div> ), and JavaScript should end it ( </div> ). It should also not do it for HTML tags like <hello> .

I've tried str. repeat str. repeat , but it didn't come out as expected. This is what I've tried:

 function inputtextarea() { let inputtextarea = document.getElementById('inputtextarea'); inputtextarea.value = inputtextarea.value.repeat(2); }

 <textarea name="inputtextarea" id="inputtextarea" cols="30" rows="10" oninput="inputtextarea()"></textarea>

Can you tell me why it is not working?

link for str.repeat

Answer 1

This is my attempt, with some work you should get something better.

Fixed some errors!

 function checkKeypress(elem, evt) { var txtBef = elem.value.slice(0, elem.selectionEnd); var txtAft = elem.value.slice(elem.selectionEnd, elem.value.lenth); var lastString = txtBef .replace(/\\s+/g, " ") /*replace multiple spaces to just one*/ .split(" "); lastString = lastString[lastString.length - 1]; if(evt.key == ">"){ if(lastString.includes("<")){ var addClose = lastString.replace(/[< >]/g, ""); //replaces < and > to blank space elem.value = txtBef+" </"+addClose+">"+txtAft; //closes the writed tag elem.selectionEnd = txtBef.length + 1; //places the cursor at the midle of the tags } } }

 textarea { width: 100%; height: 100px; }

 Write a existing or a custom HTML tag and this textarea will altomatically close it for you! <textarea onkeyup="checkKeypress(this, event)"></textarea>