当前位置：网站首页>Topic | synchronous asynchronous

Topic | synchronous asynchronous

2022-07-03 07:19:00 【Happy happy learning code】

1.

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
		console.log(1);
		console.log(2);
		console.log(3);
		</script>
	</body>
</html>

2

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
		console.log(1);
		setTimeout(function(){
			console.log(2);
		},1000)
		console.log(3);
		</script>
	</body>
</html>

3.

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
		console.log(1);
		setTimeout(function(){
			console.log(4);
		},0)
		console.log(3);
		</script>
	</body>
</html>

4.

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
	console.log(1);
	setTimeout(function(){
		console.log(2);
	},3000)
	setTimeout(function(){
		console.log(3);
	},1000)
		</script>
	</body>
</html>

5.

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
console.log('1');
setTimeout(function () {
  console.log('2');
  new Promise(function(resolve, reject) {
    console.log('promise-start2');
    resolve();
  }).then(function() {
    console.log('promise-end2');
 });
},0);
new Promise(function(resolve, reject) {
    console.log('promise-start');
    resolve();
}).then(function() {
    console.log('promise-end');
});
setTimeout(function () {
    console.log('3');
},0);
console.log('4');
		</script>
	</body>
</html>

Still don't understand promise Purpose

6. This classic , Change position casually, understand

<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
        console.log('1');
        new Promise(function(resolve, reject) {
           console.log('promise-start2');
		   // setTimeout(function () {
		   //        console.log('6');
		   // },0);
           resolve();
        }).then(function() {
			setTimeout(function () {
			       console.log('3');
			},0);
          console.log('promise-end2');
		 
        });
      
        console.log('4');
		</script>
	</body>
</html>

原网站

版权声明
本文为[Happy happy learning code]所创，转载请带上原文链接，感谢
https://yzsam.com/2022/184/202207030718508266.html