<Js>数据类型

//Number:数字    var num = new Number(1.568);    document.write("num = "+num+"<br>");    var num1 = 20.1;    document.write("num1 = "+num1+"<br>");//清空    num1 = null;    document.write("num1 = "+num1+"<br>");//无value    var num2;    document.write("num2 = "+num2+"<br><br>");

//String:字符    var str = new String("ABC");    document.write("str = "+str+"<br>");    var str1 = 'asd';    document.write("str1 = "+str1+"<br><br>");

//Array:数组    var arr = new Array("a",'d',1);    document.write("arr = "+arr+"<br>");    var arr1 = ["a",'d',1];    document.write("arr1 = "+arr1+"<br>");    arr1[0] = "dd";    arr1[1] = '12';    document.write("arr1,arr1 = "+arr1[0]+","+arr1[1]+"<br><br>");

//Boolean:布尔    var bool = true;    document.write("bool = "+bool+"<br>");    bool = false;    document.write("bool = "+bool+"<br><br>");

//Object:类    var obj = {        df:"df",        sss:'12',        ff:[1,'3',true]    }     document.write(obj["df"]+"<br>");    document.write(obj.sss);