How do I show only the first letters of a string?

2019-03-07 08:40发布

I'm prompting the user to enter their first and last name but I can't figure out how to show just their first and last initials

import javax.swing.*;
//import java.awt.*;

public class Lab2Program2 {

    public static void main (String [] args) {

    String firstName;
    String lastName;


    firstName = JOptionPane.showInputDialog(null, "What is your first name?");
    lastName = JOptionPane.showInputDialog(null, "What is your last name?");

    JOptionPane.showMessageDialog(null, " Your initials are " + 
                            firstName + " " + lastName);
    }
}

3条回答
贪生不怕死
2楼-- · 2019-03-07 09:14

firstName.charAt(0) returns the char value at the 0 index. That is the first letter of your firstName String.

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贪生不怕死
3楼-- · 2019-03-07 09:30

If you want to show a message box like you were doing before, this should work:

JOptionPane.showMessageDialog(null, 
    "Your initials are " + firstName.substring(0, 1) + " " + lastName.substring(0, 1));
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倾城 Initia
4楼-- · 2019-03-07 09:41

You can use chatAt() method.

JOptionPane.showMessageDialog(null, 
            "Your initials are " + firstName.charAt(0) + " " + lastName.charAt(0));
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