java - 代码输出 NULL 而不是值

Question

代码假设打印用户输入的名称，但它只是打印空值而不是打印实际名称。我正在使用数组来存储名称值。

import javax.swing.JOptionPane;

class PrintName {
    public static void main(String[] args) {

         int nameCount = Integer.parseInt(JOptionPane.showInputDialog(null, " how many NAMES you want to enter?"));
         String [] userFirstName = new String [nameCount];
         String [] userLastName = new String [nameCount];
         for (int i=0; i<nameCount; i++) {
             fullName(userFirstName[i], userLastName[i]);
         }

         for (int i=0; i<nameCount; i++) {
         JOptionPane.showMessageDialog(null, userFirstName[i] + "\n" + userLastName[i]);
    }

    public static void fullName (String firstName, String nLastName) {
        firstName = JOptionPane.showInputDialog(null, "What's your first name?");
        nLastName = JOptionPane.showInputDialog(null, "What's your last name?");
    }

}

Answer 1

我认为发生这种情况是因为您更改了值而不是值指针，为此更改了 fullName 的公司:

public static void fullName (String[] firstName, String[] nLastName, int i) {
    firstName[i] = JOptionPane.showInputDialog("What's your first name?");
    nLastName[i] = JOptionPane.showInputDialog("What's your last name?");
}

现在您可以通过以下方式调用该函数:

fullName(userFirstName, userLastName, i);

我希望这对你有用:)