Using the JavaScript language, have the function factorial(num) take the num parameter being passed and return the factorial of it (ie. if num = 4, return (4 * 3 * 2 * 1)).
Enter an positive integer in the input field below.
$(document).ready(function() {
function factorial(n) {
if (n === 0) {
return 1;
} else {
return n * factorial(n - 1);
}
}
$('.calculate').click(function() {
var numString = $('.data input').val(),
numValue = numString * 1;
if (numString === '' || isNaN(numValue) || parseInt(numValue) !== numValue) {
$('.result p').html('Please enter an integer in the input field.');
} else {
$('.result p').html(numValue + '! = <span>' + factorial(numValue) + '</span>');
}
});
});