Javascript 数组方法 some和filter

用法

filter过滤后返回一个新的数组，不对直接对原数组进行操作
some检查后返回一个boolean值，判断数组中是否有满足的值

    array.filter(callback[,thisargs])
    array.some(callback[,thisargs])

实例代码

filter()

eg1.

 "use strict"
   var result = Object.getOwnPropertyNames(window).filter(function (value) {//window对象的所有属性名
        var firstChar = value.substr(0, 3) //截取前三个字母
        return firstChar === "CSS"//判断是否以CSS开头

    })
    for (let i of result) {
       console.log(i)
    }

thisargs参数

eg2.
"use strict"

var arry = ["1", 15, "the", true, {"name": "xiaoming"}]
            , obj = {min: 10, max: 20}

    var result2 = arry.filter(function (value) {
        if (typeof value === "number") {
            return value > this.min && value < this.max//
        }
        return false
    }, obj)

    for (let i of result2) {
           console.log(i)//15
    }

some()

eg3.

var arry = [1, 2, 3, 4, 5, 6],
 result3=arry.some(function(value){
    return value%2===0
})
console.log(result3)//true