为什么如果在javascript中其他方法不起作用？

Question

I want an animation such that it toggles to slide the div left and right every time I click button. However, when I actually use the code it only slides it to right once and stops working any more.

<script> 
var left = 1;

$(document).ready(function(){
$("button").click(function(){

  if(left==1){
    $("div").animate({left:'250px'});
    left=2;
  }else{ 
    $("div").animate({right:'250px'});
    left=1;
  }

  });
});

</script> 

What's wrong with this code? I couldn't think of a problem.

Answer 1

Because you're using both left and right, try this:

if( left === 1 ) {
    $("div").animate({left:'250px'});
    left = 2;
}
else { 
    $("div").animate({left:'0px'});
    left = 1;
}

Answer 2

The loop was right, but the css wasn't.

<script> 
var left = 1;

$(document).ready(function(){
$("button").click(function(){
  if(left==1){
    $("div").animate({left:'250px'});
    left=2;
  }
  else { 
    $("div").animate({left:'0px'});
    left=1;
  }
 });
});

</script>