Parameter & Argument
A parameter is a variable defined in a function declaration. An argument is the actual value passed to the function when it is called.
Parameters receive data.
Arguments provide the data.
Why they are important
Parameters and arguments allow functions to work with different data. Instead of writing separate functions for each value, you can pass values dynamically. This makes programs flexible and reusable.
How parameters work
When defining a function, you specify parameters inside parentheses.
Example:
Here:
nameis a parameter- It acts as a placeholder for future input
How arguments work
When calling the function, you provide an argument.
Here:
"Alice"is the argument- It replaces the parameter
name
So inside the function, name = "Alice".
Multiple parameters
Functions can have more than one parameter.
Calling it:
Here:
aandbare parameters5and3are arguments
Key difference
- Parameter → defined in the function
- Argument → passed when calling the function
Think of it like this:
A parameter is a labeled box.
An argument is the value placed inside the box.
Why learning this matters
Understanding parameters and arguments helps you:
- Build dynamic functions
- Pass data between parts of a program
- Avoid hardcoding values
Write scalable code
Functions become powerful only when they accept input.
Related terms
- What is Function?
- What is Return Value?
- What is Variable?
Source
Simplified from general programming documentation and Wikipedia.