使用警报选择多个单选按钮 [英] Selecting Multiple Radio Buttons With Alert

问题描述

基本上，我想创建一个具有类似测验结构的页面，用户可以从一个问题中选择一个选项，从另一个问题中选择另一个选项.根据每个问题的答案，它需要提醒某个输出.我只有一些基本的 Javascript 知识，所以我使用相同的理论使用文本框选择答案，但这次我想使用单选按钮.

Basically, I want create a page that has a quiz like structure and the user can select one option from one question and another from another question. Depending on the answers to each question it would need to alert a certain output. I only have some basic knowledge of Javascript so am using the same theory of using text boxes to select an answer but this time I want to use Radio buttons.

这是带有单选按钮的页面的 HTML 代码:

This is the HTML code for the page with the radio buttons:

<p>
                <strong>1. This is the first question?</strong><br />
                <input type="radio" name="op1" value="anw1">Option 1<br>
                <input type="radio" name="op1" value="anw2">Option 2
            </p>

            <p>
                <strong>2. This is the second question?</strong><br />

                <input type="radio" name="op2" value="anw1">Option 1<br>
                <input type="radio" name="op2" value="anw2">Option 2

            </p>

            <input type='button' value='Get result!' onClick='Submit()' /><br />

然后我现在在 head 标签中有这样的功能:

I then have the function for now in the head tag like this:

function Submit()
  {

var op1 = document.getElementsByName('op1')
var op2 = document.getElementsByName('op2')


if(op1== "anw1" && op2== "anw1")
{
alert ("This would be if both options one were selected")
}

else if (op1== "anw2"&& op2== "anw2")
{
alert ("This would be if the the seconds ones were selected")
}

else
{

alert ("This would be if neither were true")

}

}

然而，我似乎无法开始工作，所以我想我可能不会以正确的方式解决这个问题，尽管我确实希望它设置类似的 .我可以让 else 部分工作，但其他部分都不行.

However, I cannot seem to get to work so I think I might be not going about this the right way though I do want it set out similar . i can get the else part to work but none of the other ones.

推荐答案

以下版本将执行您的代码尝试执行的操作:

The following version will do what your code was trying to do:

function Submit() {    
    var op1= document.getElementsByName('op1');
    var op2= document.getElementsByName('op2');

    if (op1[0].checked && op2[0].checked) {
        alert("This would be if both options one were selected");
    } else if (op1[1].checked && op2[1].checked) {
        alert("This would be if the the seconds ones were selected");
    } else {    
        alert("This would be if neither were true");
    }    
}

演示:http://jsfiddle.net/Hy9Nw/1

getElementsByName() 函数 返回一个列表(实际上是一个 HTMLCollection)，而不是单个元素，因此您不能像在代码中那样只比较 op1== "anw1" .即使它是单个元素，您也需要说 op1.value == "anw1".

The getElementsByName() function returns a list (actually an HTMLCollection), not a single element, so you can't just compare op1== "anw1" like in your code. Even if it was a single element you'd need to say op1.value == "anw1".

要访问 getElementsByName() 返回的 op1 列表中的各个项目，您可以将数组语法与 op1[0] 结合使用，并且使用 op1[0].checked 测试它是否被检查 - 返回 true 或 false.

To access the individual items in the op1 list returned by getElementsByName() you can use array syntax with op1[0], and test whether it is checked by using op1[0].checked - which returns true or false.

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