print all prime numbers before a number code example
Example 1: Write a program that prints all prime numbers less than 1,000,000
public class Main {
public static void main(String[] args) {
for (int i = 2; i < 1_000_000; ++i) {
boolean isPrime = true;
int sqrt = (int)Math.ceil(Math.sqrt(i));
for (int divisor = 2; divisor <= sqrt; ++divisor) {
if (i % divisor == 0) {
isPrime = false;
break;
}
}
if (isPrime) {
System.out.println(i);
}
}
}
}
Example 2: first n prime number finder in python
>>> def getprimes(x): primes = [] # Loop through 9999 possible prime numbers for a in range(1, 10000): # Loop through every number it could divide by for b in range(2, a): # Does b divide evenly into a ? if a % b == 0: break # Loop exited without breaking ? (It is prime) else: # Add the prime number to our list primes.append(a) # We have enough to stop ? if len(primes) == x: return primes >>> getprimes(5)[1, 2, 3, 5, 7]>>> getprimes(7)[1, 2, 3, 5, 7, 11, 13]