嵌套的 if else 语句未按预期工作

Question

程序中没有错误。 PASS、CLEARED 用户输入正在按预期工作。 但是，当我在嵌套 if 中输入 NO 作为用户输入时，控件会正确选择“else 语句”，但它也会进入内部，并执行下一个 S.O.P 显示，例如“你通过了第二级面试吗？”如果一级面试未通过，则不需要。因此，它显示 else 和 next if 相关语句。但我只想显示 else 语句并退出。

package controlStatements;

import java.util.Scanner;

class nested_if_else_Statement {

      static public void main(String[] args) {
             
            Scanner scan = new Scanner(System.in);
             
             System.out.println("Online Assesment, enter PASS or FAIL?");
             String oa = scan.nextLine();
             if (oa.equals("PASS")) {   
                 System.out.println("Please wait in the office lobby for further levels of interview.");
                 
                 System.out.println("Have you CLEARED first level of interview?");
                 String level1 = scan.nextLine();
                 if(level1.equals("CLEARED")) {
                    System.out.println("Please wait for second level of interview.");    
                 }else {
                    System.out.println("We're Sorry, better luck next time.");
                 }
                 
                 System.out.println("Have you CLEARED second level of interview?");
                 String level2 = scan.nextLine();
                 if(level2.equals("CLEARED")) {
                     System.out.println("Please wait for third level of interview.");
                 }else {
                     System.out.println("We're sorry, better luck next time.");
                 }
                 
                 System.out.println("Have you CLEARED third level of interview?");
                 String level3 = scan.nextLine();
                 if(level3.equals("CLEARED")) {
                    System.out.println("Please wait for fourth level of interview.");
                 }else {
                     System.out.println("We're sorry, better luck next time.");
                 }
                 
                 System.out.println("Have you CLEARED fourth level of interview?");
                 String level4 = scan.nextLine();
                 if(level4.equals("CLEARED")) {
                    System.out.println("Kindly wait for final level of HR Interview.");
                    System.out.println("Thank you for your patience.");
                 }else {
                    System.out.println("We're sorry, better luck next time.");
                 }
                 
                 System.out.println("Have you DONE with your HR Interview?");
                 String levelHR = scan.nextLine();
                 if(levelHR.equals("DONE")) {
                    System.out.println("Please wait in the office lobby, will get back shortly."); 
                 }
                 
             } else {
                 System.out.println("We're Sorry, better luck next time");
             }
     
             scan.close();
      }
}

Answer 1

这些声明正在按预期发挥作用。它捕获了

else

，但您从未告诉它 stop 运行，因此它继续执行下一步。解决此问题的一个简单方法是每当您想要退出代码时添加

return

语句。

if (/* whatever */) {
   // do stuff
} else {
   // do stuff
   return;
}

// other stuff that won't be ran if `return` is reached

Answer 2

您需要使用

return

将控制流直接引出函数。这将阻止控制流评估下一个条件。

class nested_if_else_Statement {
    static public void main(String[] args) {
        Scanner scan = new Scanner(System.in);
             
        System.out.println("Online Assesment, enter PASS or FAIL?");
        String oa = scan.nextLine();
        if (oa.equals("PASS")) {   
            System.out.println("Please wait in the office lobby for further levels of interview.");
                 
            System.out.println("Have you CLEARED first level of interview?");
            String level1 = scan.nextLine();
            if (level1.equals("CLEARED")) {
                System.out.println("Please wait for second level of interview.");    
            } else {
                System.out.println("We're Sorry, better luck next time.");
                return;
            }
                 
            System.out.println("Have you CLEARED second level of interview?");
            String level2 = scan.nextLine();
            if (level2.equals("CLEARED")) {
                System.out.println("Please wait for third level of interview.");
            } else {
                System.out.println("We're sorry, better luck next time.");
                return;
            }

            // ...

作为附加建议，您可以通过测试

oa.equals("PASS")

而非

!oa.equals("PASS")

来删除一定程度的缩进。通过在这种情况下尽早退出，我们可以消除一定程度的缩进。

package controlStatements;

import java.util.Scanner;

class nested_if_else_Statement {
    static public void main(String[] args) {         
        Scanner scan = new Scanner(System.in);
             
        System.out.println("Online Assesment, enter PASS or FAIL?");
        String oa = scan.nextLine();
        if (!oa.equals("PASS")) { 
            System.out.println("We're Sorry, better luck next time");
            scan.close();
            return;
        }

        System.out.println("Please wait in the office lobby for further levels of interview.");
             
        System.out.println("Have you CLEARED first level of interview?");
        String level1 = scan.nextLine();
        if (level1.equals("CLEARED")) {
            System.out.println("Please wait for second level of interview.");    
        } else {
            System.out.println("We're Sorry, better luck next time.");
            return;
        }
             
        System.out.println("Have you CLEARED second level of interview?");
        String level2 = scan.nextLine();
        if (level2.equals("CLEARED")) {
            System.out.println("Please wait for third level of interview.");
        } else {
            System.out.println("We're sorry, better luck next time.");
            return;
        }
             
        System.out.println("Have you CLEARED third level of interview?");
        String level3 = scan.nextLine();
        if (level3.equals("CLEARED")) {
            System.out.println("Please wait for fourth level of interview.");
        } else {
            System.out.println("We're sorry, better luck next time.");
            return;
        }
             
        System.out.println("Have you CLEARED fourth level of interview?");
        String level4 = scan.nextLine();
        if (level4.equals("CLEARED")) {
            System.out.println("Kindly wait for final level of HR Interview.");
            System.out.println("Thank you for your patience.");
        } else {
            System.out.println("We're sorry, better luck next time.");
            return;
        }
             
        System.out.println("Have you DONE with your HR Interview?");
        String levelHR = scan.nextLine();
        if (levelHR.equals("DONE")) {
            System.out.println("Please wait in the office lobby, will get back shortly."); 
        }
     
        scan.close();
    }
}