Programming Example
Check whether a given number is prime or not (using for loop)
A number is said to be prime if it is divisible by 1 and itself. It should not have any other divisors.
#include<stdio.h>
void main()
{
int number, i;
int indicator = 0;
printf("Enter a number to check prime or Not: ");
scanf("%d",&number);
for(i = 2; i < number/2; i++)
{
if(number%i == 0)
{
indicator = 1;
break;
}
}
if(indicator == 1){
printf(" \n Number %d is not prime. \n", number);
}
else{
printf(" \n Number %d is prime. \n", number);
}
}Enter a number to check prime or Not: 13
Number 13 is prime.
<hr>
Enter a number to check prime or Not: 15
Number 15 is not prime.
First read the algorithm, then study the program code line by line. After that, compare the code with the output and finally go through the explanation. This approach helps learners understand both the logic and the implementation properly.
After understanding this example, try to rewrite the same program without looking at the code. Then change some values or logic and run it again. This helps improve confidence and keeps learners engaged on the page for longer.