Parameter (computer science) facts for kids

In computer science, parameters are like special placeholders or labels for information that a computer program needs to do its job. Think of them as empty boxes waiting for specific details.

When you tell a part of a program, like a mini-program called a subroutine (or a function), to do something, you often need to give it some instructions or data. These pieces of information are called values. When these values are given to the subroutine, they are then known as arguments. These arguments then tell the program exactly how to run or what to do.

What are Parameters in Programming?

In programming, a parameter is a name that acts as a placeholder for a piece of data. This data will be given to a function or a subroutine when it is called. For example, if you have a function that adds two numbers, it needs two parameters to hold those numbers.

Why do we use Parameters?

Parameters make computer programs much more flexible and useful. Instead of writing a new piece of code every time you want to do a similar task with different data, you can write one function. This function uses parameters to accept different inputs.

• Reusability: You can use the same function many times with different information.
• Flexibility: The function can adapt to different situations based on the data it receives.
• Organization: It helps keep your code neat and easy to understand.

Example of using Parameters

Imagine you have a function that calculates the area of a rectangle. This function would need two pieces of information: the length and the width. These would be its parameters.

When you define the function, you might say: `calculate_area(length, width)`

Here, `length` and `width` are the parameters. They are just names for the numbers that will be given later.

Parameters vs. Arguments

The words "parameter" and "argument" are often used to mean the same thing, but in computer science, they have a small difference.

• A parameter is the name of the placeholder in the function's definition. It's like the empty box.
• An argument is the actual value that you put into that box when you use the function. It's the specific number or piece of text.

How Parameters become Arguments

Let's go back to our `calculate_area` example:

When you define the function: `calculate_area(length, width)` Here, `length` and `width` are the parameters.

When you use the function: `calculate_area(10, 5)` Here, `10` and `5` are the arguments. The value `10` is passed to the `length` parameter, and `5` is passed to the `width` parameter. The function then uses these arguments to calculate the area (which would be 50).

This way, the same `calculate_area` function can be used to find the area of any rectangle, just by giving it different arguments.

Types of Parameters

Parameters can hold different types of information, such as:

• Numbers: Like `5`, `10.5`, or `-3`.
• Text (Strings): Like `"hello"`, `"your name"`, or `"product code"`.
• True/False values (Booleans): Used for decisions, like `true` or `false`.
• Lists or Collections: A group of items, like a list of names or numbers.

The type of parameter depends on what kind of information the function needs to work correctly.