Question

I am trying to write a javascript function which is called input() (performing input validation) and it will contain 3 arguments – the arguments are message, min and max.

I am having trouble bringing/writing the the function as a whole, have managed to work out bits of the function though – any help appreciated!

Code so far:

    // declare variables

var min = 5
var max = 20
var message = 'input must be between 5 and 20';

// get user input
input = parseInt(prompt(message));

// check range
while(isNaN(input) || input<min || input>max) {
    alert('input was invalid');
    input = parseInt(prompt(message));
}

// output validation
alert('input was accepted');

(from http://jsfiddle.net/AnJym/2/)

Answer 1

looks pretty good – the last thing to do is to declare a function and put your code in the “function body”

var input = function(min, max, message) {
    // your code
    return input;
}

you could also write function input(min, max, message) { ... }, but it’s a matter of taste.

Now you can do var i = input(5, 25, "input must been 5 and 25") and i will contain the validated variable.