underscore.js _.keys[Object]

Retrieve all the names of the object's properties.

返回对象的所有的属性名称

_.keys({one : 1, two : 2, three : 3});
=> ["one", "two", "three"]

源码:

  _.keys = nativeKeys || function(obj) {
    if (obj !== Object(obj)) throw new TypeError('Invalid object');
    var keys = [];
    for (var key in obj) if (_.has(obj, key)) keys[keys.length] = key;
    return keys;
  };