---
title: 6.3 Function Parameters
description: "Function parameters are variables declared in a function's parameter list. They receive the values supplied through arguments when the function is called. ``` #include int multiply(int a, int b) { return a * b; } int main(void) { int result1…"
url: "https://edcret.in/docs/c-programming/c-functions/6-3-function-parameters/"
updated: "2026-10-27"
category: C Programming / Functions
---

# 6.3 Function Parameters

Function parameters are variables declared in a function's parameter list. They receive the values supplied through arguments when the function is called.

```
#include <stdio.h>

int multiply(int a, int b)
{
    return a * b;
}

int main(void)
{
    int result1 = multiply(4, 5);
    int result2 = multiply(6, 3);

    printf("%dn", result1);
    printf("%dn", result2);

    return 0;
}
```

### Example Output

```
20
18
```

### Explanation

The function definition declares two parameters:

```
int multiply(int a, int b)
```

Here, `a` and `b` are parameters of type `int`. Each call supplies two argument values.

```
multiply(4, 5);
multiply(6, 3);
```

During the first call, `a` receives `4` and `b` receives `5`. During the second call, `a` receives `6` and `b` receives `3`.

### Parameters and Arguments

| Term | Example | Meaning |
| --- | --- | --- |
| Parameter | `int a` | Variable declared in the function definition |
| Parameter | `int b` | Second variable declared in the function definition |
| Argument | `4` | Value supplied by the caller |
| Argument | `5` | Second value supplied by the caller |

### Functions with Different Parameter Lists

A function can accept multiple parameters of different types:

```
double calculateArea(double length, double width)
{
    return length * width;
}
```

It can also accept no parameters:

```
void display(void)
{
    printf("Readyn");
}
```

In a function definition, `void` inside the parentheses explicitly indicates that the function accepts no parameters.

The number and types of arguments must be compatible with the function's declared parameter types. C passes argument values to parameters; it does not automatically provide reference-style parameter passing.