Jul 30, 2019

Arguments or parameters?

I have a hard time remembering the difference between two common programming terms: arguments, and parameters.

This simple inability leads to real insecurity when I speak with coworkers with more education and experience. Nothing inspires imposter syndrome in a more than not remembering the fundamentals!

Here is the difference between the two similar terms:

Arguments

Arguments are the data passed to a function. Think of something simple like console.log(). In order to get a message written to the console, you need to pass it some information.

console.log('One', 2, false, null)

Every bit of information that you pass to a function is an argument. In the above example, we are assigning four arguments to console.log(): "One", 2, false, and null.

Parameters

Parameters are the data that a function is expecting. Let’s say you have a function that takes two numbers and returns the sum. It will look something like this:

function sum(a, b) {
return a + b
}

The variables that a function is expecting are its parameters. In our sum() function, we are expecting two parameters: a, and b.

Remembering the difference

I’ve been wracking my brain for a mnemonic device for remembering the difference, but have yet to come up with a great one. In the meantime, this will have to do:

Arguments are data you assign to a function, while parameters are variables that the function is prepared to accept.

If I hear of or come up with a better one, I’ll update this article.

I hope that helps!

Proverbs 4:13 (SDG)

An illustration of Sean McPherson's face

My name is Sean McPherson, and I'm a software developer and educator living in Pittsburgh, PA.

I write about React, JavaScript, accessibility, user experience, and occasionally some other topics.