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

Anurags answer is basically correct. But to support Object.keys(obj) in older browsers as well you can use the code below that is copied from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys . It adds the Object.keys(obj) method if it's not available from the browser.

if (!Object.keys) {
 Object.keys = (function() {
 'use strict';
 var hasOwnProperty = Object.prototype.hasOwnProperty,
    hasDontEnumBug = !({ toString: null }).propertyIsEnumerable('toString'),
    dontEnums = [
      'toString',
      'toLocaleString',
      'valueOf',
      'hasOwnProperty',
      'isPrototypeOf',
      'propertyIsEnumerable',
      'constructor'
    ],
    dontEnumsLength = dontEnums.length;

return function(obj) {
  if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) {
    throw new TypeError('Object.keys called on non-object');
  }

  var result = [], prop, i;

  for (prop in obj) {
    if (hasOwnProperty.call(obj, prop)) {
      result.push(prop);
    }
  }

  if (hasDontEnumBug) {
    for (i = 0; i < dontEnumsLength; i++) {
      if (hasOwnProperty.call(obj, dontEnums[i])) {
        result.push(dontEnums[i]);
      }
    }
  }
  return result;
};
}());
}