jQuery - add/append value to "rel" attribute

Question

I have a set of random links, like this:

<a rel="foo"> ... </a>
...
<a> ... </a>

Some of them may have a rel attribute, some not.

How can add a rel attribute with a value to each link, and if the link already has one, then append my value to the existing value/values?

Also how can I skip any elements with that have a certain rel attribute, like rel="ignore" ?

Answer 1

This should work fine:

$("a").each(function(index) {
    var curRel = $(this).attr("rel");
    if (curRel !== "ignore")
        $(this).attr("rel", curRel + " my value");
});

Simple iteration over all the anchors, appending your value. If rel doesn't exist curRel will just be empty string so the code won't break.

Answer 2

Short 'n sweet:

$("a[rel!='ignore']").each(function() {
    this.rel += 'theValue';
});

You can try it here.

Answer 3

var toModify = $('#xxx'); /* or how ever you identify you link */
var currentAttr = toModify.attr('rel');
if(currentAttr != 'ignore'){
    toModify.attr('rel', currentAttr + '_asd');
}