Js全局变量和局部变量

2018-07-04 本文已影响0人小姨家错对门

var a;
function send(){
 a = "Javascript";
 var b = "语言基础";
 console.log(a+b);
}
send();

//结果: Javascript语言基础

var a = "PHP";
function send(){
 a = "Javascript";
 var b = "语言基础";
 console.log(a+b);
}
send();

//结果: Javascript语言基础

var a = "PHP";
function send(){
 a = "Javascript";
 var b = "语言基础";
 console.log(a+b);
}
send();
console.log(a);

//结果:
Javascript语言基础
Javascript

var a = "PHP";
function send(){
 var a = "Javascript";
 var b = "语言基础";
 console.log(a+b);
}
send();
console.log(a);

//结果:
Javascript语言基础
PHP

是不是很简单哪~~~