前端开发中ES6的Promise
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title></title>
</head>
<body>
<script>
var a=0
var test=function(resolve, reject){
setTimeout(function(){
a=4;
console.log(a)
if(a<2){resolve('200 OK');}
if(a>2){reject('400 died');}
},3000)
}
var p1=new Promise(test);
p1.then(function(resolve){
console.log(resolve)
},function(reject){
console.log(reject);
})
</script>
</body>
</html>