java - 总是返回 false

Question

这个问题已经有答案了:

How do I compare strings in Java? (23 个回答)

已关闭 9 年前。

我被要求执行一个程序，在其中检查用户输入的名称是否在我在计算机上创建的文件中。我编写了代码，它没有显示任何编译错误，但是当它运行时， boolean 表达式始终为 false。请帮我解决这个问题。男孩名字文件中的样本名字是 Martin，女孩名字中的样本名字是 Emily。

import java.util.*;
import java.io.*;
public class nameSearch1
{
    public boolean readingGirlNames () throws IOException
    {
        String[] girlNames = new String [200];
        int i = 0;
        File file = new File ("GirlNames.txt");
        Scanner inputFile = new Scanner(file);

        while(inputFile.hasNext() && i < girlNames.length )
        {
            girlNames [i] = inputFile.nextLine();
            i++;
        }
        inputFile.close();

        Scanner keyboard=new Scanner(System.in);
        boolean girlName = false ;
        nameSearch object4 = new nameSearch();
        System.out.println(" Enter the Girl Name you wish to see : ");

        String nameCheckGirl = keyboard.nextLine();

        for ( int index = 0 ; index < 200 ; index ++ )
        {
            if( nameCheckGirl == girlNames[index])
            { 
                girlName = true;
            }

        }
        return girlName;
    }

    public boolean readingBoyNames () throws IOException
    {
        String[] boyNames = new String [200];
        int i = 0;
        File file = new File ("BoyNames.txt");
        Scanner inputFile = new Scanner(file);

        while(inputFile.hasNext() && i < boyNames.length )
        {
            boyNames [i] = inputFile.nextLine();
            i++;

        }
        inputFile.close();




        nameSearch object2 = new nameSearch ();
        Scanner keyboard=new Scanner(System.in);
        boolean boyName = false ;

        System.out.println(" Enter the Boy Name you wish to see : ");

        String nameCheckBoy = keyboard.nextLine();

        for ( int index = 0 ; index < 200 ; index ++ )
        {
            if( nameCheckBoy == boyNames[index])
            { 
                boyName = true;
            }

        }
        return boyName;
    }

    public static void main(String[]Args)
    {
        Scanner keyboard = new Scanner(System.in);

        nameSearch1 object1 = new nameSearch1 ();

        try
        {
            System.out.println(" The search result for the Girl's name is : " + object1.readingGirlNames ());
        }
        catch (IOException ioe)
        {
            System.out.println(" Exception!!! ");

            ioe.printStackTrace();
        }

        try
        {
            System.out.println(" The search result for the Boy's name is : " + object1.readingBoyNames ());
        }
        catch (IOException ioe)
        {
            System.out.println(" Exception!!! ");

            ioe.printStackTrace();
        }

    }
}

Answer 1

为什么要将字符串与 == 运算符更改与 equals() 进行比较

if( nameCheckBoy.equals(boyNames[index]))
            { 
                boyName = true;
            }