[Java] BigData basis _switch statement

grammar

Switch (expression) {
   Case X:
     // code block 
    BREAK ;
   Case Y:
     // code block 
    BREAK ;
   default :
     // block 
}

switchStatement works like this:

• switchThe expression is evaluated once.
• The value of the expression of each casecomparison value.
• If it matches, the code associated with the block is executed.
• breakAnd defaultkeyword is optional

Real case

package cn.test.logan.day05;

import java.util.Scanner;

public class ShopMenu {
    public static void main(String[] args) {
        System.out.println ( "Welcome to the Logan mall, select the action you want!" );
        
        Scanner sc = new Scanner(System.in);
        boolean flag = true;
        while(flag) {
            System.out.println ( "1. browse merchandise; 2 shopping; 3. View Cart; 4. modify the cart; 5. submitted orders; 6. payment; 7 Exit" );
             // user input 
            String cmd = sc.nextLine ();
            
            switch(cmd) {
            case "1":
                System.out.println ( ". 1) eggplant 2.5 / kg \ n2) Maize 8 / kg \ n3) Orange 12 is / kg \ n-" );
                 BREAK ;
             Case "2" :
                System.out.println ( "are shopping ....." );
                 BREAK ;
             Case "3" :
                System.out.println ( "viewing shopping ....." );
                 BREAK ;
             Case "4" :
                System.out.println ( "being modified cart ....." );
                 BREAK ;
             Case "5" :
                System.out.println ( "is being submitted orders ....." );
                 BREAK ;
             Case "6" :
                System.out.println ( "Payment in ....." );
                 BREAK ;
             Case "7" :
                flag = false;
                break;
            default:
                System.out.println ( "select items you entered is not valid ...." );
            }
        }
        
        
        
    }
}

ShopMenu.java