只允许空格、字母、退格和制表符

Question

I'm using Firefox to test my script out. My goal is to allow white space, letters, backspace and tab to work, but for some reason I could break my code and type in a number which I don't want. How can I fix this issue?

This is what I have so far:

                $(document).ready(function () {
                    $("#inputTextBox").keypress(function (event) {
                        var inputValue = event.which;

                        //Backspace ASCII = 8 
                        //Tab ASCII = 9 
                        if (!(inputValue >= 65 && inputValue <= 123)) {
                            if (inputValue === 8 && inputValue === 9){
                                event.preventDefault();
                            }
                        }
                        console.log(inputValue);
                    });

Answer 1

if (inputValue === 8 && inputValue === 9)这个条件永远不会通过，你的 var 不能同时等于 8 和 9，你应该使用 ||

Answer 2

This is what worked for me. This allows letters, white space, backspace and tab. I'm going to leave it here in case someone needs it.

                $(document).ready(function () {
                    $("#inputTextBox").keypress(function (event) {
                        var inputValue = event.which;
                        //Allow letters, white space, backspace and tab. 
                        //Backspace ASCII = 8 
                        //Tab ASCII = 9 
                        if (!(inputValue >= 65 && inputValue <= 123)
                            && (inputValue != 32 && inputValue != 0)
                            && (inputValue != 48 && inputValue != 8)
                            && (inputValue != 9)){
                                event.preventDefault(); 
                        }
                        console.log(inputValue);
                    });