数据类型
var a = 95;
//Number
var b = 'name';
//String
var c = function(){
return 'Hello World';
};
//String
var d = 10/+0;
//Number(+Infinity)
var g = 10/-0;
//Number(-Infinity)
var l = 10/'a';
//Number(NaN)
var e = null;
//Object
var f = undefined;
//Undefined
