Underscore.JS flatten方法

_.flatten(array, [shallow])

var _ = require('underscore');

var list = [1, [2], [4], 5, [[6]]]
//Example 1: flatten list
result = _.flatten(list);
console.log(result)

//Example 2: flatten list to first level only 
result = _.flatten(list, true);
console.log(result)

>node tester.js

[ 1, 2, 4, 5, 6 ]
[ 1, 2, 4, 5, [ 6 ] ]