gistfile1.txt

package Test;

import java.util.Scanner;

public class Test1 {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.println("enter a number:");
		int a = input.nextInt();
		if(a == 2){
			System.out.println("2是質數");
		}
//		 int c =  (int)Math.sqrt(a);
//		 if(c <= 1){
//			 c ++;
//		 }
//		 else{
//			 c = c;
//		 }
		for(int b = 2;b < a; b++){
			if(a%b==0){
//				boolean isPrime = false;
				System.out.println(a+"不是質數");
				break;
			}
			else if(b == a - 1){
//				boolean isPrime = true;
				System.out.println(a+"是質數");
		}
		
	}
	}
}