JavaScript奇技淫巧

Posted 2020-09-10 且听风吟V

1.JSON转换

//var str = ‘ {"name": "heihei","age": "12"}‘;
//var obj = {"name": "heihei","age": "12"};
//JSON.parse(str).log//将JSON格式字符串，转化成JSON格式对象
//JSON.stringify(obj).log//将JSON格式对象，转化成JSON格式字符串

2.JS 异常捕捉

try {
    console.log(num)
}catch (e) { // 形参必须写，形参名字 自己定义，一般起名e
    console.log(‘出错了‘);
    console.log(e.message);// e.message 收集当前代码报错的原因
    throw new Error(‘你长得太丑了，不准打开此页面‘)
}finally {
    console.log(‘不管是否报错都要执行这里‘); // 一般不使用

3.类数组 转换 成数组

function toAry (n1, n2, n3, n4, n5) {
   var ary = [].slice.call(arguments);
    var aryTwo = Array.prototype.slice.call(arguments);
    console.log(ary,aryTwo);
} // IE 6-8不兼容
toAry(1,2,3,4,5);
// 兼容写法
function  toA (obj) {
    var ary = [];
    for (var i=0; i<ary.length;i++) {
        ary[ary.length] = obj[i]
    }
    return ary;
}
toA()

4.utils

function listToArray (obj) {
    var ary = [];
    try {
        ary = Array.prototype.slice.call(obj)
    }catch (e) {
        for (var i=0; i<obj.length;i++) {
            ary[ary.length] = obj[i]
        }
    }
    return ary;
}
function JSONParse (str) {
    var val;
    try {
        val = JSONParse(str)
    }catch (e){
        val = eval("("+str+")");
    }
    return val;
    return JSON in window ? JSONParse(str):eval("("+str+")");
}

5.Main

var main = {
    JSONTrans: function (obj) {
        if (window.JSON) {
            return JSON.parse(obj);
        }else {
            return eval("("+ obj +")");
        }
    },
    tryJson: function (obj) {
        var res = null;
        try {
            res = JSON.parse(obj);
        } catch (e) { // 储存的是报错信息,必须要写
            res = eval("(" + obj + ")");
        }
        return res;
    },
    toAr: function (n) {
        // var newAry  = Array.apply(null,n);//通过构造函数以函数身份运行,来创建数组.这个方法在IE8以下不兼容传类数组
        var newAry2  = [].slice.call(n);// 调用数组中的slice克隆数组的方法,改变方法中this的指向

        return newAry2;
    }
};

6.中文排序

  var aryNew = [
            {name:‘小满‘,age:3}, // AXUAN
            {name:‘张‘,age:12},// DAWEISUOYAO
            {name:‘帅哥‘,age:63},// SHUAIGE
            {name:‘猥琐哥‘,age:103},// WEISUOGE
            {name:‘盛尧‘,age:2004},// SHENGYAO
            {name:‘安迪‘,age:15}// LIYUAN
        ];
        var theAry = aryNew.sort(function (a, b) {
            return  a.name.localeCompare(b.name);

        });
        console.log(theAry);