为什么在Switch那里报错unreachable code

Question

import java.util.Scanner;

public class hellojava {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
int num=0;

    do{
        System.out.println("请输入1-7，输入0退出");
         num = input.nextInt();

        if(num>7|| num<0);{
            System.out.println("输入数字不合格");
            continue;
        }    
        switch(num) {
        case 1:
            System.out.println("1");
            break;
        case 2:
            System.out.println("2");
            break;
        case 3:
            System.out.println("3");
            break;
        case 4:
            System.out.println("4");
            break;
        case 5:
            System.out.println("5");
            break;
        case 6:
            System.out.println("6");
            break;
        case 7:
            System.out.println("7");
            break;

        }
    }while(num!=0);
    System.out.println("程序结束");
}

}

Answer 1