Learning practice: comprehensive application of cycle and branch structure (I)

1、 Use double loop to output 99 multiplication table

public class Test1 {

	public static void main(String[] args) {
		int i ,j;
		// The outer loop outputs the first multiplier , The loop inside outputs the second multiplier 
		for(i = 1;i <= 9;i++) {
			for(j = 1;j <= i;j++) {
				System.out.print(i+" * "+j+" = "+i * j+"\t");
				if(j == i) {
					System.out.print("\n");
				}
			}
		}

	}

}

  The output sample is as above

2、 Enter an integer from the keyboard , When the input 1~7 when , Output “ Monday ”~“ Sunday ”  When entering other numbers , Prompt the user to re-enter , Input 0 End the program at .

package homework2;

import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		int day;
		 do{
			System.out.println(" Please enter 1--7 Number between , Input 0 Exit procedure ");
			day = input.nextInt();
			// Input 1 To 7 Output the corresponding week , Enter other non 0 Digital pop-up prompt 
			switch(day) {
			case 0:
				break;
			case 1:
				System.out.println(" Monday ");
				break;
			case 2:
				System.out.println(" Tuesday ");
				break;
			case 3:
				System.out.println(" Wednesday ");
				break;
			case 4:
				System.out.println(" Thursday ");
				break;
			case 5:
				System.out.println(" Friday ");
				break;
			case 6:
				System.out.println(" Saturday ");
				break;
			case 7:
				System.out.println(" Sunday ");
				break;
			default:
				System.out.println(" The input data must be 0 To 7 Between ");
			}
		}while(day!=0);
		 // Input 0 End the program at 
		 System.out.println(" Program end ");
	}

}

The test example is as above  

3、 The digital pyramid

package homework3;

import java.util.Scanner;

public class Test {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.println(" Please enter an integer ");
		int n = input.nextInt();
		int i,j,k;
		// The following loop outputs the number of lines 
		for(i = 1;i<=n;i++) {
			// The following loop outputs spaces 
			for(j=0;j<=n-i;j++) {
				System.out.print(" ");
			}
			// The following loop outputs numbers 
			for(k=1;k<=2*i-1;k++) {
				System.out.print(i);
			}	
			System.out.print("\n");
		}
	}
}

The test example is as above