Getting JavaScript object key list

Question

I have a JavaScript object like

var obj = {
   key1: \'value1\',
   key2: \'value2\',
   key3: \'value3\',
   key4: \'value4\'
}

How can I

Answer 1

using slice, apply and join method.

var print = Array.prototype.slice.apply( obj );
alert('length='+print.length+' list'+print.join());