Underscore.JS isWeakMap方法

_.isWeakMap(object)

var _ = require('underscore');

//Example 1: Check if argument passed is a WeakMap
console.log(_.isWeakMap(new WeakMap()));

//Example 2: Check if argument passed is a WeakMap
console.log(_.isWeakMap('Test'));

>node tester.js

true
false