Js标签定义:
labelname:
代码块
Js标签引用:
break labelname;
continue labelname;
实例1(Js标签控制多重循环)
outerloop:
for (var i = 0; i < 10; i++)
{
innerloop:
for (var j = 0; j < 10; j++)
{
if (j > 3)
{
break;
}
if (i == 2)
{
break innerloop;
}
if (i == 4)
{
break outerloop;
}
document.write("i=" + i + " j=" + j + "<br>");
}
}
实例2(Js标签+break跳出任意代码块)
<script>
cars=["BMW","Volvo","Saab","Ford","Lisa"];
list:{
document.write(cars[0] + "<br>");
document.write(cars[1] + "<br>");
document.write(cars[2] + "<br>");
break list;
document.write(cars[3] + "<br>");
document.write(cars[4] + "<br>");
}
</script>
上述break list语句会跳出list的代码块。如果将break换成continue会有“惊喜”,因为违反了continue语句只能用于循环代码块中,而list只是个普通代码块,不是循环。