方法一:

public class Prime{
    public static void prime(int number){
        int sumCount=0;//輸出次數
        for (int i=1;i<=number;i++){
            int count=0; //整除次數
            for (int j=1;j<=i;j++){
                if(i%j==0){  
                    count++; 
                }
            }
            if
 
 (count==2){ //質數的定義
                    System.out.print(i+"\t");
                    sumCount++;
                    if(sumCount%8==0){ //每輸出8個換行
                        System.out.println();
                    }
            }
        }
    }

方法二:

public class Prime02 {
    public static void main (String[] args){
        int
 
 count=0;//輸出次數
        for (int i = 2; i <= 100; i++) {//1不是質數,直接從2開始
            int j=2;
            for (j = 2; j <= i; j++) {
                if (i % j == 0){
                    break;              
                }
            }
            if(i==j){
                System.out.print(i+"\t");
                count++;
                if
 
(count%8==0){
                    System.out.println();
                }
            }
        }
    }
}

方法三:

public class Prime03 {
    public static void main (String[] args){
        int count=0;//輸出次數

        for (int i = 2; i <= 100; i++) {//1不是質數,直接從2開始
            boolean flag=true;
            for (int j=2; j <i ; j++) {
                if (i % j == 0){
                    flag=false;
                    break;
                }
            }
            if(flag){
                System.out.print(i+"\t");
                count++;
                if(count%8==0){
                    System.out.println();
                }
            }
        }
    }
}

效果截圖: