2016-05-26 42 views
2

我希望將圖片從燈泡關閉更改爲燈泡上的兩個按鈕的點擊。我在W3schools中看到過類似的例子,但是,我無法看到代碼之間的區別。請幫忙。我的代碼有什麼問題?(使用javascript更改圖片)

<!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> 

回答

5

switchreserved keyword不能作爲參數名中使用

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

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

+0

謝謝!得到它了。 –