大家能帮我看看我问题出现在哪里吗🙏

Question

package in;
import java.util.Scanner;

public class in {

public static void main(String[] args) {
        Scanner sc=new Scanner (System.in);
        System.out.println("请输入优 良 中 不及格");
         agum(sc.next());
}
public static void agum(String a)
{
    
    int b = 1;
    
    if(a=="优")
    {
        b=0;
    }
    if(a=="良")
    {
        b=1;
    }
    if(a=="中")
    {
        b=2;
    }
    if(a=="不及格")
    {
        b=3;
    }
    
    switch(b)
    {
        case 0:System.out.print("Excellent");break;
        case 1:System.out.print("Good");break;
        case 2:System.out.print("Average");break;
        case 3:System.out.print("Fail");break;
    }
}

}

Answer 1

字符串的判断不能用等于号，要用equals()

import java.util.Scanner;
class in {
public static void main(String[] args) {
        Scanner sc=new Scanner (System.in);
        System.out.println("请输入优 良 中 不及格");
         agum(sc.next());
}
public static void agum(String a)
{
    int b = 1;
    if(a.equals("优"))
    {
        b=0;
    }
    if(a.equals("良"))
    {
        b=1;
    }
    if(a.equals("中"))
    {
        b=2;
    }
    if(a.equals("不及格"))
    {
        b=3;
    }
    switch(b)
    {
        case 0:System.out.print("Excellent");break;
        case 1:System.out.print("Good");break;
        case 2:System.out.print("Average");break;
        case 3:System.out.print("Fail");break;
    }
  }
}