underscore.js _.isEqual[Object]

Performs an optimized deep comparison between the two objects, to determine if they should be considered equal.

用于比较两个对象的值是否相当，而不是内存引用位置.

var moe   = {name : 'moe', luckyNumbers : [13, 27, 34]};
var clone = {name : 'moe', luckyNumbers : [13, 27, 34]};
moe == clone;
=> false
_.isEqual(moe, clone);
=> true

源码:

 _.isEqual = function(a, b) {
    return eq(a, b, []);
  };