Javascript复选框onChange

使用onclick事件，因为每次单击复选框都会改变它。

function calc()
{
if (document.getElementById('xxx').checked)
{
document.getElementById('totalCost').value = 10;
} else {
calculate();
}
}

超文本标记语言

<input type="checkbox" id="xxx" name="xxx" onclick="calc();"/>

如果你正在使用jQuery..那么我可以提出以下建议: 注意:我在这里做了一些假设

$('#my_checkbox').click(function(){
if($(this).is(':checked')){
$('input[name="totalCost"]').val(10);
} else {
calculate();
}
});

下面的解决方案使用jquery。让我们假设你有一个id为checkboxId的复选框。

const checkbox = $("#checkboxId");


checkbox.change(function(event) {
var checkbox = event.target;
if (checkbox.checked) {
//Checkbox has been checked
} else {
//Checkbox has been unchecked
}
});

var checkbox = $("save_" + fieldName);
checkbox.onclick = function(event) {
var checkbox = event.target;


if (checkbox.checked) {
//Checkbox has been checked
} else {
//Checkbox has been unchecked
}
};

Javascript

  // on toggle method
// to check status of checkbox
function onToggle() {
// check if checkbox is checked
if (document.querySelector('#my-checkbox').checked) {
// if checked
console.log('checked');
} else {
// if unchecked
console.log('unchecked');
}
}

超文本标记语言

<input id="my-checkbox" type="checkbox" onclick="onToggle()">

纯javascript:

const checkbox = document.getElementById('myCheckbox')


checkbox.addEventListener('change', (event) => {
if (event.currentTarget.checked) {
alert('checked');
} else {
alert('not checked');
}
})

My Checkbox: <input id="myCheckbox" type="checkbox" />

试一试

totalCost.value = checkbox.checked ? 10 : calculate();

function change(checkbox) {
totalCost.value = checkbox.checked ? 10 : calculate();
}


function calculate() {
return other.value*2;
}

input { display: block}

Checkbox: <input type="checkbox" onclick="change(this)"/>
Total cost: <input id="totalCost" type="number" value=5 />
Other: <input id="other" type="number" value=7 />

我知道这似乎是一个新手的答案，但我把它放在这里，这样它可以帮助其他人在未来。

假设您正在用foreach循环构建一个表。同时在最后添加复选框。

<!-- Begin Loop-->
<tr>
<td><?=$criteria?></td>
<td><?=$indicator?></td>
<td><?=$target?></td>
<td>
<div class="form-check">
<input type="checkbox" class="form-check-input" name="active" value="<?=$id?>" <?=$status?'checked':''?>>
<!-- mark as 'checked' if checkbox was selected on a previous save -->
</div>
</td>
</tr>
<!-- End of Loop -->

你在表格下面放置一个按钮，隐藏输入:

<form method="post" action="/goalobj-review" id="goalobj">


<!-- we retrieve saved checkboxes & concatenate them into a string separated by commas.i.e. $saved_data = "1,2,3"; -->


<input type="hidden" name="result" id="selected" value="<?= $saved_data ?>>
<button type="submit" class="btn btn-info" form="goalobj">Submit Changes</button>
</form>

你可以这样写你的脚本:

<script type="text/javascript">
var checkboxes = document.getElementsByClassName('form-check-input');
var i;
var tid = setInterval(function () {
if (document.readyState !== "complete") {
return;
}
clearInterval(tid);
for(i=0;i<checkboxes.length;i++){
checkboxes[i].addEventListener('click',checkBoxValue);
}
},100);


function checkBoxValue(event) {
var selected = document.querySelector("input[id=selected]");
var result = 0;
if(this.checked) {


if(selected.value.length > 0) {
result = selected.value + "," + this.value;
document.querySelector("input[id=selected]").value = result;
} else {
result = this.value;
document.querySelector("input[id=selected]").value = result;
}
}
if(! this.checked) {


// trigger if unchecked. if checkbox is marked as 'checked' from a previous saved is deselected, this will also remove its corresponding value from our hidden input.


var compact = selected.value.split(","); // split string into array
var index = compact.indexOf(this.value); // return index of our selected checkbox
compact.splice(index,1); // removes 1 item at specified index
var newValue = compact.join(",") // returns a new string
document.querySelector("input[id=selected]").value = newValue;
}


}
</script>

您的复选框的id将在结果变量中以字符串“1,2”的形式提交。然后，您可以在控制器级别按照自己的意愿将其分解。

HTML:

<input type="checkbox" onchange="handleChange(event)">

JS:

function handleChange(e) {
const {checked} = e.target;
}