C program to count number of digits in a number; Through this tutorial, you will learn how to count or find number of digits in a number in c program using For Loop, While Loop, Functions, and Recursion.

**Algorithm to count the number of digits in a number**

Use the following steps to write a program to count number of digits in a number; as follows:

- Read integer number and store it into a variable.
- Initialize another variable to store total digits say count = 0.
- If num > 0 then increment count by 1 i.e. count++.
- Divide num by 10 to remove the last digit of the given number i.e. num = num / 10.
- Repeat step 3 to 4 till num > 0 or num != 0.
- Print number of count in a number

## Programs to Count Number of Digits in a Number in C

Let’s use the following program to count number of digits in a number in c using for loop, while loop, function and recursion:

- C Program to Count Number of Digits in a Number using While Loop
- C Program to Count Number of Digits in a Number using For Loop
- C Program to Count Number of Digits in a Number Using Functions
- C Program to Count Number of Digits in a Number Using Recursion

### C Program to Count Number of Digits in a Number using While Loop

```
/* C Program to Count Number of Digits in a Number using While Loop */
#include <stdio.h>
int main()
{
int Number, Reminder, Count=0;
printf("\n Please Enter any number :- ");
scanf("%d", &Number);
while(Number > 0)
{
Number = Number / 10;
Count = Count + 1;
}
printf("\n Number of Digits in a Given Number = %d", Count);
return 0;
}
```

The output of the above c program; as follows:

Please Enter any number :- 123456 Number of Digits in a Given Number = 6

### C Program to Count Number of Digits in a Number using For Loop

```
/* C Program to Count Number of Digits in a Number using For Loop */
#include <stdio.h>
int main()
{
int Number, Reminder, Count;
printf("\n Please Enter any number :- ");
scanf("%d", &Number);
for (Count=0; Number > 0;Number=Number/10)
{
Count=Count + 1;
}
printf("\n Number of Digits in a Given Number = %d", Count);
return 0;
}
```

The output of the above c program; as follows:

Please Enter any number :- 145698 Number of Digits in a Given Number = 6

### C Program to Count Number of Digits in a Number Using Functions

```
/* C Program to Count Number of Digits in a Number using While Loop */
#include <stdio.h>
int Count_Of_Digits (int Number)
{
int c = 0;
while(Number > 0)
{
Number = Number / 10;
c = c + 1;
}
printf("\n Number of Digits in a Given Number = %d", c);
}
int main()
{
int Number;
printf("\n Please Enter any number :- ");
scanf("%d", &Number);
Count_Of_Digits (Number);
return 0;
}
```

The output of the above c program; as follows:

Please Enter any number :- 123456789 Number of Digits in a Given Number = 9

### C Program to Count Number of Digits in a Number Using Recursion

```
/* C Program to Count Number of Digits in a Number Using Recursions */
#include <stdio.h>
int Count_Of_Digits (int);
int main()
{
int Number, Count = 0;
printf("\n Please Enter any number :- ");
scanf("%d", &Number);
Count = Count_Of_Digits (Number);
printf("\n Number of Digits in a Given Number = %d", Count);
return 0;
}
int Count_Of_Digits (int Number)
{
static int Count =0;
if(Number > 0)
{
Count = Count + 1;
Count_Of_Digits (Number / 10);
}
return Count;
}
```

The output of the above c program; as follows:

Please Enter any number :- 41236 Number of Digits in a Given Number = 5