1、break：跳出循环
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>点击下面的按钮，测试带有break语句的循环</p>
<button onclick="myFunction()">点我点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x="",i=0;
for (i=0;i<10;i++){
if(i==3){
break;
}
x=x+"该数字为"+i+"<br>";
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
2、continue 用于跳过循环中的一个迭代
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>点击下面的按钮，测试带有break语句的循环</p>
<button onclick="myFunction()">点我点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x="",i=0;
for (i=0;i<10;i++){
if(i==3){
continue;
}
x=x+"该数字为"+i+"<br>";
}
document.getElementById("demo").innerHTML=x;
}
</script>
</body>
</html>
3、使用 For…In 声明来遍历数组内的元素
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>now test</title>
</head>
<body>
<p>点击下面的按钮，循环遍历对象“person”的属性</p>
<button onclick="myFunction()">点我点我</button>
<p id="demo"></p>
<script>
function myFunction(){
var x;
var txt="";
var person={fname:"Billtui",lname:"Galltes",age:56};
for (x in person){
txt=txt +person[x];
}
document.getElementById("demo").innerHTML=txt;
}
</script>
</body>
</html>