I just saw the following: .asp
And wonder if there's something wrong with selectObject.value. Why not a simple approach:
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
function displayResult(){
alert(document.getElementById("mySelect").value);
}
</script>
</head>
<body>
<form>
Select your favorite fruit:
<select id="mySelect">
<option value="apple">Apple</option>
<option value="orange">Orange</option>
<option value="pineapple">Pineapple</option>
<option value="banana">Banana</option>
</select>
</form>
<button type="button" onclick="displayResult()">
Display value of selected fruit
</button>
</body>
</html>
It seems to be working with no problem.
Thanks in advance!
Mike
I just saw the following: http://www.w3schools./jsref/prop_option_value.asp
And wonder if there's something wrong with selectObject.value. Why not a simple approach:
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript">
function displayResult(){
alert(document.getElementById("mySelect").value);
}
</script>
</head>
<body>
<form>
Select your favorite fruit:
<select id="mySelect">
<option value="apple">Apple</option>
<option value="orange">Orange</option>
<option value="pineapple">Pineapple</option>
<option value="banana">Banana</option>
</select>
</form>
<button type="button" onclick="displayResult()">
Display value of selected fruit
</button>
</body>
</html>
It seems to be working with no problem.
Thanks in advance!
Mike
Share Improve this question edited Jun 9, 2012 at 3:39 Derek 朕會功夫 94.5k45 gold badges198 silver badges253 bronze badges asked Jun 9, 2012 at 3:23 MoriMori 6,96219 gold badges70 silver badges104 bronze badges 5- 12 Don't pay too much attention to w3schools. – Pointy Commented Jun 9, 2012 at 3:25
-
Radio buttons require a convoluted process to access, but I've never had similar issues with
<select>inputs. – Scott Stevens Commented Jun 9, 2012 at 3:28 -
Well, I've thought for years that you had to go the way of using the
selectedIndexwhen getting aselects value. However, reviewing MDN's information onselectproperties, it appears I was wrong and it is available for accessing the (first)optionelement's selected value. Am I missing something, or was I just lead astray? Now I'm wondering if theselectedIndexwas was meant for accessing multi-selectvalues. Anybody care to disabuse me, please be my guest. Also, MDN is a legitimate resource for learning. – Jared Farrish Commented Jun 9, 2012 at 3:40 - @Pointy: It's not just W3Schools -- I've seen that method in many other references too. – Mori Commented Jun 9, 2012 at 3:43
- 2 You might take a look at MDN's Javascript Learning offerings, as well as the articles offered on the MDN Javascript Reference site. But yeah, w3schools is a bit discredited on SO, even though probably most of it is not "wrong". Just not necessarily dependable credible (w3fools.). – Jared Farrish Commented Jun 9, 2012 at 3:44
1 Answer
Reset to default 5Your method, document.getElementById("mySelect").value is returning the value of the select object - which sets itsself to the value of the currently selected option. The way w3Schools is doing it is finding the actual option tag, then you're getting the value of the option tag. So, as long as you are accessing the currently selected option tag, they return the exact same thing. However, the w3schools way allows you to actually set the value of the option tag instead of changing which option is selected when setting the value property (although that's probably not what you want).
Example:
<select id='select'>
<option value=1>one</option>
<option value=2>two</option>
</select>
x=document.getElementById("mySelect").selectedIndex;
So, document.getElementById('select').value; returns the value of the select element.
And document.getElementsByTagName("option")[x].value; returns the value of the selected option element.
Meaning that document.getElementById('select').value=2 changes which option is selected, while document.getElementsByTagName("option")[x].value=2 changes the value of the selected option element.
TLDR: When getting the value there is no difference, when setting the value there is.
发布者：admin，转转请注明出处：http://www.yc00.com/questions/1744168414a4561415.html
评论列表（0条）