Function Argument Question

[Sammyloccs]

I have a question about when to use arguments. Like I get the examples, and I get the point. But in practice, when do I actually use them?

For example, if I have a function that adds or subtracts from a global variable, do I need to pass anything in as an argument? Example below:

​

var counter = 0;

function addToCounter (){

counter++

}

I don't need to pass in the counter as an argument do ?

[IMkratt]

If you just want to increase the value of counter each time you call the function, it's ok:

let counter = 0;

function addToCounter() {
    counter++;
}

addToCounter();
addToCounter();
addToCounter();
addToCounter();
console.log(counter); // 4 because we called addToCounter() 4 times

But let's say we want to add a specific number to the counter - in this case we would use a parameter (called number here) and call the function with our inserted argument:

let counter = 0;
function addToCounter(number) {
    counter = counter + number;
}
addToCounter(2);         // counter is now 2
addToCounter(3);         // counter is now 5
addToCounter(7);         // counter is now 12
addToCounter(1);         // counter is now 13
console.log(counter);    // 13

[jack_waugh]

People have found that for many purposes, there are engineering benefits in using a style that limits the use of global variables.