Here's a program to print prime numbers in C:
#include #include int main() { int i, num, isPrime; printf("Enter an integer: "); scanf("%d", &num); for(i=2; i<=num; i++) { isPrime = 1; int j; for(j=2; j<=sqrt(i); j++) { if(i%j==0) { isPrime = 0; break; } } if(isPrime == 1) { printf("%d\n", i); } } return 0; }
Explanation:
The program takes an integer input from the user and stores it in the variable num
.
A for loop is used to iterate from 2 to the input number num
.
Another for loop is used inside the first loop to check if the current number is divisible by any number between 2 and its square root. If it is divisible, the isPrime
flag is set to 0, and the inner loop breaks.
If the isPrime
flag is still 1 after the inner loop, it means the number is prime, and it is printed to the console.
Note: This program uses the sqrt
function from the math.h
library to calculate the square root of a number.