zoukankan      html  css  js  c++  java
  • js对象2

    /*
    var obj = {
        "a" : 1
    }
    */
    // 获取数据
    //console.log( obj.a );
    //console.log( obj['a'] );
    
    // 设置
    //obj.a = 2;
    //obj.b = 3;
    //obj['c'] = 4;
    //console.log( obj );
    
    //var b = 'c';
    //obj[b] = 5;
    //console.log( obj );
    
    
    /*
    console.log( div1.style.color );
    console.log( div1.style['color'] );
    console.log( div1['style']['color'] );
    */
    
    
    /*
    var arr = ['a','b','c'];
    //console.log( typeof(arr) );    // 'object'
    for( var i in arr ){
        console.log( typeof(i), i );
    }
    */
    
    
    /*
    var obj = {"a":1, "b":2, "i":3};
    //console.log( obj[0] );
    for( var i in obj ){
        //console.log( typeof(i), i, obj[i] );
        console.log( obj['i'] );
        //console.log( obj.i );
    }
    */
    
    
    
    // 判断数据是否为数组
    //var obj = {"a":1, "b":2};
    //var arr = ["a", "b", "c"];
    
    //alert( typeof(obj) );    //'object'
    //alert( typeof(arr) );    //'object'
    
    //var b1 = Array.isArray(obj);
    //var b2 = Array.isArray(arr);
    //console.log( b1, b2 );
    
    //console.log( obj.length, arr.length );
    
    //arr instanceof Array 判断arr在其原型链中是否存在 Array 这个构造函数的 prototype 属性。
    //var b = arr instanceof Array;
    //console.log(b);
    
    
    
    /*
    //  判断某个属性在对象中是否存在
    var obj = {
        a : 1,
        b : undefined
    }
    
    var b = 'a' in obj;
    console.log( b );
    
    //var b = obj['b'];
    //console.log( b );
    */
    
    /*
    var obj = {
        a : 1
    }
    console.log( obj.a );
    var r = delete obj.b;
    console.log( obj.a );
    console.log( r );
    */
    
    
    
    //var arr = ["a", "b", "c", "a"];
    // 某个成员在数组中是否存在
    //var i = arr.indexOf("d");    
    // 如果"a"在arr数组中存在,则返回"a"的下标,如果不存在,则返回-1
    //console.log( i );
    //console.log( arr )    //["a", "b", "c"]
  • 相关阅读:
    【转】i18n实现前端国际化(实例)
    【转】SQL Pretty Printer for SSMS 很不错的SQL格式化插件
    windows server IIS启用Windows authentication
    【转】命令行下载各种网上各种视频
    解决python “No module named pip”
    【转】excel音标乱码
    【转】自动化部署之jenkins及简介
    【转】右键菜单管理
    【转】C# @作用
    【转】NGen
  • 原文地址:https://www.cnblogs.com/l8l8/p/8698321.html
Copyright © 2011-2022 走看看