Accessing variables from other functions without using global variables

I think your best bet here may be to define a single global-scoped variable, and dumping your variables there:

var MyApp = {}; // Globally scoped object

function foo(){
    MyApp.color = 'green';
}

function bar(){
    alert(MyApp.color); // Alerts 'green'
} 

No one should yell at you for doing something like the above.

To make a variable calculated in function A visible in function B, you have three choices:

• make it a global,
• make it an object property, or
• pass it as a parameter when calling B from A.

If your program is fairly small then globals are not so bad. Otherwise I would consider using the third method:

function A()
{
    var rand_num = calculate_random_number();
    B(rand_num);
}

function B(r)
{
    use_rand_num(r);
}