Question

I have come across this javascript code.

var digit_name = function() {
    var names = ['zero', 'one','two'];
    return function(n) {
        return names[n];
    };
}();

alert(digit_name(1));

The output is one. I understand that the inner function is being assigned to the variable digit_name. What is the need for adding parentheses in the 6th line after the code of outer function. Can anyone tell what exactly is going on?

Answer 1

The ending () you see make that outer function execute immediately. So digit_name ends up storing the resulting inner function, as opposed to a pointer to the outer function.

For more information see: What is the purpose of a self executing function in javascript?