alerts in else statements
Question
Why won't this code work correctly? If someone selects something with an id of of '1599' then an alert will show "$1,599.00". If the id does not match, then the alert should show "$1,499.00". But it doesn't. Could someone help me figure this out?
thanks
<html>
<script type="text/javascript">
function showPrice(){
var a = document.getElementById();
if (a == "1599"){
alert("$1,599.00");
}
else {
alert("$1,499.00");
}
}
<body>
<div class="hc_right">
<input type="button" class="spc" value="Price" onclick="showPrice()" />
<p class="price" id="1599">$1,599.00</p>
</div>
<div class="hc_right">
<input type="button" class="spc" value="Price" onclick="showPrice()" />
<p class="price" id="1499">$1,499.00</p>
</div>
</div>
</body>
</html>
3 answers
solution1
1 2011-05-27 02:22:39
You need to let showPrice know which element you want to show the alert for. Right now, you're not actually selecting anything with the document.getElementById ( a will be either null or undefined at this point).
There are a bunch of different ways to go about doing this, but to keep it close to your current implementation, I might do something like this:
HTML
<div class="hc_right">
<input type="button" class="spc" value="Price" onclick="showPrice(1599)" />
<p class="price" id="1599">$1,599.00</p>
</div>
<div class="hc_right">
<input type="button" class="spc" value="Price" onclick="showPrice(1499)" />
<p class="price" id="1499">$1,499.00</p>
</div>
</div>
Javascript
function showPrice(a){
if (a == "1599"){
alert("$1,599.00");
}
else {
alert("$1,499.00");
}
return false;
}
solution2
0 2011-05-27 02:20:36
I think you will see the issue if you add an alert(a); before the if(...) -- My guess is that you aren't getting the value you expect in there.
solution3
0 2011-05-27 02:20:42
The document.getElementById() method takes a parameter of the ID to look for. Something like:
document.getElementById("1599")
and will return the document element that has that ID. Not sure what it will return when no parameter is passed.
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