//using plane javascript
if(document.getElementById('on_or_off_checkbox').checked) {
//I am checked
}
//using jQuery
if($('#on_or_off_checkbox').is(':checked')){
//I am checked
}const checkbox = document.getElementById('myCheckbox')
checkbox.addEventListener('change', (event) => {
if (event.currentTarget.checked) {
alert('checked');
} else {
alert('not checked');
}
})
//HTML INPUT VVVVVVVVVVVVVV
<input id="myCheckbox" type="checkbox" /><input type='checkbox' onchange='handleChange(this);'> Checkbox
function handleChange(checkbox) {
if(checkbox.checked == true){
document.getElementById("submit").removeAttribute("disabled");
}else{
document.getElementById("submit").setAttribute("disabled", "disabled");
}
}