javascript - 如何获取所选单选按钮的值？(How to get the selected radio button’s value?)

Question

I'm having some strange problem with my JS program.(我的JS程序遇到一些奇怪的问题。)

I had this working properly but for some reason it's no longer working.(我的工作正常，但由于某种原因，它不再工作。) I just want to find the value of the radio button (which one is selected) and return it to a variable.(我只想查找单选按钮的值（已选中该按钮）并将其返回给变量。) For some reason it keeps returning undefined .(由于某种原因，它总是返回undefined 。)

Here is my code:(这是我的代码：)

function findSelection(field) {
    var test = 'document.theForm.' + field;
    var sizes = test;

    alert(sizes);
        for (i=0; i < sizes.length; i++) {
            if (sizes[i].checked==true) {
            alert(sizes[i].value + ' you got a value');     
            return sizes[i].value;
        }
    }
}

submitForm :(submitForm ：)

function submitForm() {

    var genderS =  findSelection("genderS");
    alert(genderS);
}

HTML:(HTML：)

<form action="#n" name="theForm">

    <label for="gender">Gender: </label>
    <input type="radio" name="genderS" value="1" checked> Male
    <input type="radio" name="genderS" value="0" > Female<br><br>
    <a href="javascript: submitForm()">Search</A>
</form>

  ask by mkyong translate from so

Answer 1

JavaScript:(JavaScript：)

var radios = document.getElementsByName('genderS');

for (var i = 0, length = radios.length; i < length; i++)
{
 if (radios[i].checked)
 {
  // do whatever you want with the checked radio
  alert(radios[i].value);

  // only one radio can be logically checked, don't check the rest
  break;
 }
}

http://jsfiddle.net/Xxxd3/610/(http://jsfiddle.net/Xxxd3/610/)

Edit: Thanks HATCHA and jpsetung for your edit suggestions.(编辑：感谢HATCHA和jpsetung的编辑建议。)