Question

我试图使用fullname设置对象person的{{1}}属性，但在注销全名时未定义。

this

这很奇怪，因为在函数内部使用var person = { name:'yask', fullname: this.name + ' Srivastava' } console.log(person.fullname);时会引用该对象。在这里它看起来像是被引用到全局对象。（窗口可能......？）

Answer 1

您可以使用getter，

来完成此操作

package receiverhost;

import java.io.*;
import java.net.*;

public class ReceiverHost {
public static void main(String[] args) throws Exception {

    //set up socket on port 5000
    ServerSocket Server = new ServerSocket(5000);

    //set up "cookie"/ text file to be written to/ read from eventually
    Writer DB = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("CQ.txt"), "utf-8"));

    System.out.println("TCPServer Waiting for client on port 5000");

    while(true){

        //declare string fromclient
        String fromclient; 
        Socket connected = Server.accept();
        System.out.println(" The client" + " " + connected.getInetAddress() + ":" + connected.getPort() + " is connected ");

        //read/ retrieve client output stream
        BufferedReader inFromClient = new BufferedReader(new InputStreamReader(connected.getInputStream()));

            fromclient = inFromClient.readLine();
            if(fromclient.equals("Q1C")){
                //write to CQ.txt
                DB.write("Q1: correct");
            }

            if(fromclient.equals("Q2C")){
                //write to CQ.txt
                DB.write("Q2: correct");
            }
        }
    }
}

基本上，你的案例中的var person = { name:'yask', get fullname(){ return this.name + ' Srivastava' } } console.log(person.fullname);会将~~词汇范围~~的上下文指向对象的功能，而不是对象本身。

在javascript

1 个答案: