錯誤：<identifier>期望nm =「Sam」;

Question

import java.util.*; 

public abstract class Player { 
    abstract String nm; 
    public abstract void displayDetails(); 
} 

class Booking extends Player { 
nm = "Sam";   

    void displayDetails() { 
     System.out.println("Name is:" + nm); 
    } 
} 

//代碼產生錯誤：identifier expected nm =「sam」;

Answer 1

在Java中，只能在塊內保留表達式。你不能在那裏保留nm = "Sam";，在實例初始化塊內移動它

import java.util.*; 

public abstract class Player { 
    String nm; // instance fields cant be declared as abstract 
    public abstract void displayDetails(); 
} 

class Booking extends Player { 
    { // instance initialization block 
     nm = "Sam"; 
    } 

    void displayDetails() { 
     System.out.println("Name is:" + name); 
    } 
}