Question

我希望在两个按钮的点击上将图片从灯泡关闭更改为灯泡。我在W3schools中看到了类似的例子，但是，我看不到代码之间的区别。请帮忙。

<!doctype html>
<html>
<body>
<script>
function light(switch){
    var pi;
    if(switch == 0){
        pi = "pic_bulboff.gif"
    }
<!--this is if the switch value is zero-->
    else{
        pi = "pic_bulbon.gif"
    }
<!--this is if switch value is anything else including 1-->
    document.getElementById('sw').src = pi;
}
</script>

<img id="sw" src="pic_bulboff.gif">

<button onclick="light(0)">Light off</button>
<button onclick="light(1)">Light on</button>
</body>
</html>

Answer 1

switch是reserved keyword，不能用作参数名称

＆＃13;

function light(s) { //Change argument name
  var pi;
  if (s == 0) {
    pi = "pic_bulboff.gif";
  } else {
    pi = "pic_bulbon.gif";
  }
  document.getElementById('sw').src = pi;
  document.getElementById('sw').title = pi; //Just to demonstrate
}

＆＃13;

<img id="sw" src="pic_bulboff.gif">

<button onclick="light(0)">Light off</button>
<button onclick="light(1)">Light on</button>

＆＃13;

我的代码怎么了？（使用javascript更改图片）

1 个答案: