javascript - 单选按钮在 ie 中不起作用

Question

我的表单中有 4 个单选按钮，一旦我提交表单，应该选中任何单选按钮，否则将显示一条警告消息。它在 chrome、firefox 中工作正常，但在 ie 中，我检查了 radion，它总是显示警报，所以我无法提交表单，我在下面给出了我的代码，请帮助我

PHP:

<form action="user_register.php" method="POST" name="myForm" onsubmit="return validateForm()" enctype="multipart/form-data">
    <label>USERNAME:</label></td>
    <input type="text" name="username" class="regtext" required/>
    <label>RESIDING CITY:</label></td>
    <input type="text" name="city" class="regtext" required/>
    <label>I'M A</label>
    <label>ARTIST &nbsp <input type="radio" value="1" name="user_type" >    </label>&nbsp
    <label>MODEL &nbsp <input type="radio" value="2" name="user_type"></label>&nbsp
    <label>COMPOSER &nbsp <input type="radio" value="3" name="user_type" ></label>&nbsp<br>
    <label>BEAT MAKER &nbsp <input type="radio" value="4" name="user_type" ></label>&nbsp
    <label>NONE &nbsp <input type="radio" value="0" name="user_type" ></label>
    <label> <input type="checkbox" value="1" name="letter" > &nbsp  I WOULD LIKE TO RECEIVE YOUR NEWSLETTER</label>
    </div>
    <div class="mainhead">
        <input type="submit" name="register" class="submit" value="SEND AND REGISTER NOW">
    </div>
</form>

JS:

<script type="text/javascript">
    function validateForm() {
        var province = document.forms["myForm"]["province"].value;
        if (province == 0 ) {
            alert("Select Province");
            document.myForm.province.focus() 
            return false;
        }
        var user_type = document.forms["myForm"]["user_type"].value;
        if (user_type == null || user_type == "") {
            alert("Select Who You are");
            return false;
        }
        var letter = document.forms["myForm"]["letter"].value;
        if (letter == null || letter == "") {
            alert("Select that you want to receive news letter");
            return false;
        }
    }
</script>

Answer 1

问题是对于 IE，document.forms["myForm"]["user_type"] 是一个 HTMLCollection 并且没有 value

解决办法是改变

var user_type = document.forms["myForm"]["user_type"].value;

到

var user_type = document.querySelector('form[name="myForm"] input[name="user_type"]:checked').value;