C Program to Count Number of Digits in a Number

In this tutorial, i am going to show you how to count or find number of digits in a number in c program with the help of 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

All C Programs to Count Number of Digits in a Number

• 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 result 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 result 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 result 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 result of the above c program; as follows:

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

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