Example Program Using 'for' Loop

Unlike any programming, language loops play a very important role in C or C++ . Here is some example program using for loop.

C Program to print n natural number using for loop:

A natural number is a number that occurs commonly and obviously in nature. As such, it is a whole, non-negative number. The set of natural numbers, denoted N, can be defined in either of two ways: N = {0, 1, 2, 3, …}

#include<studio.h>
void main()
{
    int i;
    printf("Enter any value");
    scanf("%d",&i);
    for(j=1;j<=i;j++)
    {
       printf("Value of j is now %d\n",j);
    }
}

C program to find prime no between n value given by user:

A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. The first few prime numbers are 1,2, 3, 5, 7, 11, 13, 17, 19, 23, and 29.

#include<stdio.h>
void main()
{
 int i,j,n,count=0;
 clrscr();
 printf("Enter n term value to search prime");
 scanf("%d",&n);
 for (i=1;i<=n;i++)
 {
 count=0;
 for ( j =1 ; j <= i ; j++ )
 {
 if ( i % j == 0 )
 count=count+1;
 }
 if ( count<=2 )
 printf("Prime number.=%d\n",i);
 }
 getch();
}

Output

C Program to check how many number are divisible by 5 and 3 between given range by user:

When one number can be divided by another and the result is an exact whole number. Example: 15 is divisible by 3, because 15 ÷ 3 = 5 exactly. In this case, we use logical “&&” for checking two conditions, if here any condition returns false the whole expression is return false.

#include <stdio.h>
 
int main()
{
 int range1,range2, result,i;
 printf("Enter Start value of range:");
 scanf("%d",&range1);
 printf("Enter End value of range:");
 scanf("%d",&range2);
 printf("##################################################");
 printf(" The following No is divisible by 5 and 3 both");
 printf("##################################################");
 for(i=range1; i<=range2; i++)
 {
    if (i%5==0 && i%3==0)
    {
        printf("%d \t",i); //\t is escape sequence used to put a tab
    }
 }
 getch();
 return 0;
}

Output

C Program to print Fibonacci series:

Fibonacci series is sequence of number like that 0,1,1,2,3,5,8,13…….n . The basic algorithm is {3rd number = 1st number + 2nd number} and 1st and 2nd number can start with any natural number. for example, you can start series with 4,5,9,14,23…….n . In mathematics and computer science, this sequence has many application.

 #include<stdio.h>
 
int main()
{
 int n, fn = 0, sn = 1, tmp, k;
 
 clrscr();
 printf("Enter the number of terms\n");
 scanf("%d",&n);
 
 printf("First %d terms of Fibonacci series are :-\n",n);
 
 for ( k = 0 ; k < n ; k++ )
 {
    printf("%d\t",fn);
 
    tmp = fn + sn;
    fn = sn;
    sn = tmp;
 
 
 }
 getch();
 return 0;
}

Output

C Program to calculate factorial of a given number:

In mathematics, the factorial of a non-negative integer n, denoted by “n!”, is the product of all positive integers less than or equal to n. n! = n*(n-1)*(n-2)*(n-3)…3.2.1 and zero factorial is defined as one i.e. 0! = 1.

#include <stdio.h>
 
int main()
{
 int i, v, fact = 1;
 clrscr();
 printf("Enter a number to calculate it's factorial\n");
 scanf("%d", &v);
 if (v==0)
 { 
 fact=1;
 printf("Factorial of %d = %d\n", v, fact);
 }
 else
 {
 
 for (i = 1; i <= v; i++)
 {
 fact = fact * i;
 }
 
 printf("Factorial of %d = %d\n", v, fact);
 }
 getch();
 return 0;
}

Output