jQuery - check element if it's existed

This is the correct way of doing this

if($('.myClass').length > 0) {

    // blah ...

}

Some people ask, why the following doesn't work??

if($('.myClass')) {

    // blah ...

}

Well, it's because jQuery selector always returns you an Object. 

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Of course, if you are using plain javascript, then it is correct.  For example,

var home = document.getElementById("home");

if(home) {
  // blah ...
}