javascript - How do I remove last character from input field on click?

the simple answer is, if you are using jquery, to do something like this:

//select the button, add a click event
$('#myButtonId').on('click',function () {
    //get the input's value
    var textVal = $('#myInputId').val();
    //set the input's value
    $('#myInputId').val(textVal.substring(0,textVal.length - 1));
});