如何创建一个键盘事件，让我只使用退格键和数字（在键盘和小键盘之上）？

Question

function handleSpinnerInput(event) {

    var keyID = event.keyCode
    if (keyID < 48 || keyID > 57 ) {
        /*
         * If it isn't a number, pretend the key was never pressed at all. This
         * key range works for both the number pad and the numbers on the top of
         * the keyboard. I've tested this on IE, Firefox, and Chrome to verify
         * it works on the latest version. However, I need this to work on Firefox v.31.
         */
        event.preventDefault();
        return false;
    }
}

I am using the onkeydown() function to invoke on an input field but only the top number of the keyboard work and it doesn't even let me type the backspace in the older version. I see that the numpad keycodes are 96-105 and the backspace keycode is 46. how would I include that in my conditional and should I set it to ignore keycodes that are not the ones specified?

EDIT: the code in top worked with the onkeypress() function but I have since changed it to onkeydown() since it didnt work on older firefox.

EDIT: function handleSpinnerInput(event) {

var keyCode = event.keyCode ;
if(!(Number(keyCode) >= 0 && Number(keyCode) <= 9) && keyCode != 'Backspace') 

    event.preventDefault();
    return false;
}

}

Answer 1

Use:

 let input = document.querySelector('input') input.addEventListener('keydown', handleSpinnerInput) function handleSpinnerInput(event) { if(.(Number(event.key) >= 0 && Number(event.key) <= 9) && event.key != 'Backspace') // Checks whether the key is different from the number or backspace event.preventDefault() }

 <input type="text">

OR

 function handleSpinnerInput(event) { console.log(event.keyCode) let isNumber = (event.keyCode >= 48 && event.keyCode <= 57) || (event.keyCode >= 96 || event.keycode <= 105) let backspace = event.keyCode == 46 if(.isNumber && !backspace) event.preventDefault() }

 <input type="text" onkeydown="handleSpinnerInput(event)">

Doubts? comment