Write a C program to input any number from user and find cube of the given number using function. How to find cube of a given number using function in C programming. Write a C function to find cube of a given number.

**Example**

**Input**

Input any number: 5

**Output**

Cube of 5 = 125

## Required knowledge

Basic C programming, Functions, Returning value from function

Must know – Program to find power of two number.

## Declare function to find cube of a number

Cube of a number `num` is `cube = num * num * num`

. This is easy, but we need to write a separate function for this simple statement.

- First assign a meaningful name to the function, say
`cube()`

. - The function should accept a number whose cube is to be calculated. Hence, function definition is
`cube(double num)`

. - Finally, the function should return cube of
`num`passed. Hence, return type of function should be`double`

.

After observing above points function declaration looks like `double cube(double num);`

**Note: ** Instead of taking `double`

as parameter and return type. You can also use `int`

, `float`

or any other integer/fractional types. However, `double`

fits best for the above requirement.

## Program to find cube using function

```
/**
* C program to find cube of any number using function
*/
#include <stdio.h>
/* Function declaration */
double cube(double num);
int main()
{
int num;
double c;
/* Input number to find cube from user */
printf("Enter any number: ");
scanf("%d", &num);
c = cube(num);
printf("Cube of %d is %.2f", num, c);
return 0;
}
/**
* Function to find cube of any number
*/
double cube(double num)
{
return (num * num * num);
}
```

Learn more – Program to find power using recursion.

**Important note: ** Inside `cube()`

function you can also use a temporary variable to store cube of `num`. Which is

```
double cube(double num)
{
double c = num * num * num;
return c;
}
```

However, the above approach is not worth. In addition, it increases complexity to declare a useless variable `c`. Instead we can directly return cube of `num` as in first approach.

`%.2f`

prints fractional numbers up to 2 decimal places. You can also use `%f`

, to print fractional numbers up to 6 decimal places (default).

Output

Enter any number: 5 Cube of 5 is 125.00

Happy coding ðŸ˜‰

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