question6.java

java课程的资料以及实验的代码

class PrimeNumberCheck
{
	public static void main(String args[])
	{
		int length=args.length;
		if (length<1)
		{
			System.out.println("invalid number of arguments\n");
			System.exit(1);
		};
		int number=Integer.parseInt(args[0]);
		if (number<1)
		{
			System.out.println("invalid argument\n");
			System.exit(1);
		};
		int i;//internal loop variable
		boolean status=true;
		loop: for (i=2;i<=(int)Math.sqrt(number);i++)
		if (number%i==0)
		{
			status=false;
			break loop;
		};
		if (status) System.out.println("prime\n");
		else System.out.println("not prime\n");
	}
}