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Is there any special reason why jQuery addClass () is not editing?

<div id="myDiv" class=" blueberry mango "></div>

If we use . addClass ()

 $("#myDiv").addClass("carrot");

The class for myDiv now "(no-space)blueberry mango(double-space)carrot"

There is left-trim , but there are double spaces between mango and carrots because there was no right-trim

  • Is there any special reason why jQuery addClass() not a right trim?
  • Or was the left trim not even intended?
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3 answers

JQuery seems to do the trimming after adding the class. See jquery addclass code below,

 addClass: function( value ) { var classNames, i, l, elem, setClass, c, cl; if ( jQuery.isFunction( value ) ) { return this.each(function( j ) { jQuery( this ).addClass( value.call(this, j, this.className) ); }); } if ( value && typeof value === "string" ) { classNames = value.split( rspace ); for ( i = 0, l = this.length; i < l; i++ ) { elem = this[ i ]; if ( elem.nodeType === 1 ) { if ( !elem.className && classNames.length === 1 ) { elem.className = value; } else { //HERE IS APPENDS ALL CLASS IT NEEDS TO ADD setClass = " " + elem.className + " "; for ( c = 0, cl = classNames.length; c < cl; c++ ) { if ( !~setClass.indexOf( " " + classNames[ c ] + " " ) ) { setClass += classNames[ c ] + " "; } } elem.className = jQuery.trim( setClass ); } } } } return this; }

So, as shown below,

jQuery.trim(" blueberry mango " + " " + "carrot")

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This is because jQuery adds the class to the list of classes, and then runs trim for the entire line.

Check out the source for addClass to see what happens.

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Looking at the source, I assume that there is no reason for this:

 setClass = " " + elem.className + " "; for ( c = 0, cl = classNames.length; c < cl; c++ ) { if ( !~setClass.indexOf( " " + classNames[ c ] + " " ) ) { setClass += classNames[ c ] + " "; } } elem.className = jQuery.trim( setClass );

True, the presence of a space before and after each class helps to find whether there is a new class (added) or not, but still they can replace the first line:

 setClass = " " + jQuery.trim(elem.className) + " ";

and still work the same ...

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