In this tutorial, i am going to show you how to find first digit of a number in c program using log() & pow() , while loop and functions.
All C Program to Find First Digit Of a Number
- C Program to Find First Digit Of a Number using Log10() and pow()
- C Program to Find First Digit Of a Number using While Loop
- C Program to Find First Digit Of a Number using Function
C Program to Find First Digit Of a Number using Log10() and pow()
/* C Program to Find First Digit Of a Number */
#include <stdio.h>
#include <math.h>
int main()
{
int Number, FirstDigit, Count;
printf("\n Please Enter any Number that you wish : ");
scanf("%d", & Number);
Count = log10(Number);
FirstDigit = Number / pow(10, Count);
printf(" \n The First Digit of a Given Number %d = %d", Number, FirstDigit);
return 0;
}
The result of the above c program; as follows:
Please Enter any Number that you wish : 123 The First Digit of a Given Number 123 = 1
C Program to Find First Digit Of a Number using While Loop
/* C Program to Find First Digit Of a Number */
#include <stdio.h>
int main()
{
int Number, FirstDigit;
printf("\n Please Enter any Number that you wish : ");
scanf("%d", & Number);
FirstDigit = Number;
while(FirstDigit >= 10)
{
FirstDigit = FirstDigit / 10;
}
printf(" \n The First Digit of a Given Number %d = %d", Number, FirstDigit);
return 0;
}
The result of the above c program; as follows:
Please Enter any Number that you wish : 2365 The First Digit of a Given Number 2365 = 2
C Program to Find First Digit Of a Number using Function
#include <stdio.h>
#include <math.h>
int First_Digit(int num);
int main()
{
int Number, FirstDigit;
printf("\n Please Enter any Number that you wish : ");
scanf("%d", & Number);
FirstDigit = First_Digit(Number);
printf(" \n The First Digit of a Given Number %d = %d", Number, FirstDigit);
return 0;
}
int First_Digit(int num)
{
while(num >= 10)
{
num = num / 10;
}
return num;
}
The result of the above c program; as follows:
Please Enter any Number that you wish : 7895 The First Digit of a Given Number 7895 = 7