JavaScript switch case 的用法实例[范围]

几个例子:

  

复制代码 代码如下:

  function case1(num){

  switch(num){

  case 1:

  document.writeln("show 1!!");

  break;

  case 2:

  document.writeln("show 2!!");

  break;

  case 3:

  document.writeln("show 3!!");

  break;

  default:

  document.writeln("show others!!");

  break;

  }

  }

  function case2(num){

  switch(num){

  case 1:

  document.writeln("show 1!!");

  //沒有break,所以會繼續執行case 2

  case 2:

  document.writeln("show 2!!");

  break;

  case 3:

  document.writeln("show 3!!");

  //沒有break,所以會繼續執行case 4

  case 4:

  document.writeln("show 4!!");

  break;

  default:

  document.writeln("show others!!");

  break;

  }

  }

  function case3(num){

  switch(num){

  case 1:

  case 2:

  //相當於if(num==1 || num==2)

  document.writeln("show 1 or 2!!");

  break;

  case 3:

  case 4:

  //相當於if(num==3 || num==4)

  document.writeln("show 3 or 4!!");

  break;

  default:

  //相當於else

  document.writeln("show others!!");

  break;

  }

  }

  function case4(num){

  switch(f(num)){

  case 1:

  case 2:

  //相當於if(num==1 || num==2)

  document.writeln("show 1 or 2!!");

  break;

  case 3:

  case 4:

  //相當於if(num==3 || num==4)

  document.writeln("show 3 or 4!!");

  break;

  default:

  //相當於else

  document.writeln("show others!!");

  break;

  }

  }

  function f(num){

  return num;

  }

  function case5(num){

  switch(num<=2){

  case true:

  document.writeln("num <= 2");

  break;

  case false:

  document.writeln("num > 2");

  break;

  }

  }

  JavaScript switch case 语句设置范围

  

   [Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]