C Program to Count Number of Digits in a Number

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:

1. Read integer number and store it into a variable.
2. Initialize another variable to store total digits say count = 0.
3. If num > 0 then increment count by 1 i.e. count++.
4. Divide num by 10 to remove the last digit of the given number i.e. num = num / 10.
5. Repeat step 3 to 4 till num > 0 or num != 0.
6. 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

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