In javascript, the tab key in textarea is scaled down.

In javascript, the tab key in textarea is scaled down.

This example describes how to scale down the tab key in textarea using javascript. Share it with you for your reference. The details are as follows:

I searched for related solutions on the Internet. The other solutions were solved using two or three lines of javascript, but there were some minor problems. JQuery is also very concise.

The javascript code in this article implements the function of entering the TAB key in TEXTAREA and auto indent. However, this Code cannot be normally executed in Google browsers.
Copy codeThe Code is as follows: sel paievent.srcelement.doc ument. selection. createRange ()
This sentence will cause an error:
Ncaught exception TypeError: Cannot read property 'selection 'of undefined

The code runs normally in IE as follows:

<mce:script type="text/javascript"><!-- function editTab() {   var code, sel, tmp, r   var tabs=""   event.returnValue = false   sel =event.srcElement.document.selection.createRange()   r = event.srcElement.createTextRange()   switch (event.keyCode)   {     case (8)  :       if (!(sel.getClientRects().length > 1))       {         event.returnValue = true         return       }       code = sel.text       tmp = sel.duplicate()       tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)       sel.setEndPoint("startToStart", tmp)       sel.text = sel.text.replace(/^/t/gm, "")       code = code.replace(/^/t/gm, "").replace(//r/n/g, "/r")       r.findText(code)       r.select()       break     case (9)  :       if (sel.getClientRects().length > 1)       {         code = sel.text         tmp = sel.duplicate()         tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)         sel.setEndPoint("startToStart", tmp)         sel.text = "/t"+sel.text.replace(//r/n/g, "/r/t")         code = code.replace(//r/n/g, "/r/t")         r.findText(code)         r.select()       }       else       {         sel.text = "/t"         sel.select()       }       break     case (13)  :       tmp = sel.duplicate()       tmp.moveToPoint(r.getBoundingClientRect().left, sel.getClientRects()[0].top)       tmp.setEndPoint("endToEnd", sel)       for (var i=0; tmp.text.match(/^[/t]+/g) && i<tmp.text.match(/^[/t]+/g)[0].length; i++)  tabs += "/t"       sel.text = "/r/n"+tabs       sel.select()       break     default   :       event.returnValue = true       break   } } // --></mce:script>

Use Time:
Copy codeThe Code is as follows: <textarea cols = 80 rows = 20 name = "input" onkeydown = "editTab ()"> </textarea>

I hope this article will help you design javascript programs.