Javascript入门(四)条件控制语句

<script type="text/javascript">

     var num = 1
     if( num == 3 ){
         alert("1");
     }
     else if( num == 2 )
    {
         alert("2");
     }
     else if( num == 1 )
    {
         alert("1");
     }
     else
    {
         alert("0");
     }

</script>

<script type="text/javascript">

     var num = 1
     switch(num){

      case 1:
              alert(‘1‘);
              break;
     case 2:
              alert(‘2‘);
              break;
     case 3:
              alert(‘3‘);
              break;
    default:
             alert(‘0‘);

    }

</script>