如何使用javascript验证多个复选框
如何使用javascript验证多个复选框
提问于 2012-10-17 12:18:18
我有多个复选框和单选按钮的简单页面，这只是验证第一个系统复选框并跳过下一个通信复选框。我是js的新手，我相信这是一个简单的修复方法。感谢您的帮助！
if (countSelected(formElement, 'checkbox', 'system[]') == 0) {
alert('Please select System Access');
return false;
}
if (countSelected(formElement, 'radio', 'department') == 0) {
alert('Please choose a Department');
return false;
}
if (countSelected(formElement, 'checkbox', 'comm[]') == 0) {
alert('Please select Comm Access');
return false;
}
return true;
}如何让它验证多个复选框？我是否还需要对多组单选按钮应用相同的修复程序？
回答 2
Stack Overflow用户
回答已采纳
发布于 2012-10-17 12:31:40
我认为问题是你从函数return太快了。试试这个：
function test() {
var valid = true;
if (countSelected(formElement, 'checkbox', 'system[]') == 0) {
alert('Please select System Access');
valid = false;
}
if (countSelected(formElement, 'radio', 'department') == 0) {
alert('Please choose a Department');
valid = false;
}
if (countSelected(formElement, 'checkbox', 'comm[]') == 0) {
alert('Please select Comm Access');
valid = false;
}
return valid;
}这样，它会验证您想要的一切，alerts验证您需要的内容，returns验证您所期望的有效性。
另一个选项是，您可以这样做，而不是在每次验证时都发出警报：
function test() {
var valid = true;
var messages = [];
if (countSelected(formElement, 'checkbox', 'system[]') == 0) {
messages.push('Please select System Access');
valid = false;
}
if (countSelected(formElement, 'radio', 'department') == 0) {
messages.push('Please choose a Department');
valid = false;
}
if (countSelected(formElement, 'checkbox', 'comm[]') == 0) {
messages.push('Please select Comm Access');
valid = false;
}
if (messages.length > 0) {
alert(messages.join("\n"));
}
return valid;
}在本例中，您在最后得到一个包含所有错误的alert。对用户来说可能更好。
Stack Overflow用户
发布于 2012-10-17 13:46:59
<script defer="defer" type="text/javascript"><!--function validateForm(formElement) {
if (formElement.first_name.value.length < 2)
return focusElement(formElement.first_name,
'Please enter a First Name that is at least 2 characters long.');
if (formElement.last_name.value.length < 2)
return focusElement(formElement.last_name,
'Please enter a Last Name that is at least 2 characters long.');
if (formElement.model_id.value.length < 7)
return focusElement(formElement.model_id,
'Please enter a Model ID that is at least 7 characters long.');
if (countSelected(formElement, 'checkbox', 'system[]') == 0) {
alert('Please select System Access');
return false;
}
if (countSelected(formElement, 'radio', 'department') == 0) {
alert('Please choose a Department');
return false;
}
if (countSelected(formElement, 'checkbox', 'comm[]') == 0) {
alert('Please select Comm Access');
return false;
}
return true; } function focusElement(element, errorMessage) {
alert((errorMessage.length > 0) ? errorMessage :
'You did not enter valid data; Please try again');
if (element.select) element.select();
if (element.focus) element.focus();
return false; } function countSelected(formElement, inputType, inputName) {
if (inputType == null) inputType = 'checkbox';
var returnValue = 0;
for (var loopCounter = 0; loopCounter < formElement.length; loopCounter++) {
var element = formElement.elements[loopCounter];
if (element.type == inputType && element.checked == true) {
if (inputName.length > 0)
if (element.name == inputName)
returnValue++;
else
returnValue++
}
}
return returnValue; } function countSelectedOptions(selectElement) {
var returnValue = 0;
for (var loopCounter = 0; loopCounter < selectElement.options.length; loopCounter++)
if (selectElement.options[loopCounter].selected == true)
returnValue++;
return returnValue;} //-->
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原文链接：
https://stackoverflow.com/questions/12927029
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