Question

我对编程比较陌生，我目前正在尝试完成我的一个教程。本教程的目的是设置8个原始数据类型，打印它们，然后重新分配新值并打印它们。我遇到的问题是，当我重新分配变量的值时，它仍会打印原始值。我的代码如下：

import javax.swing.JOptionPane;

public class week02tutorial02 {

public static void main(String[] args) {
    byte element = 63 ;
    short speed = 1192 ;
    int age = 10;
    long tfn = 987_654_321 ;
    float height = 161.5f ;
    double weight = 80.4 ;
    boolean alive = true ;
    char firstinitial = 'C';

    String tutorial = "Favourite element: " +element+"\n"
            + "Running Speed: "+speed+"kph\n"
            + "Age: "+age+"\n"
            + "Tax File Number: "+tfn+"\n"
            + "Height: "+height+"cm\n"
            + "Weight: "+weight+"Kg\n"
            + "Still Alive: "+alive+"\n"
            + "First Initial: "+firstinitial+"\n";
    JOptionPane.showMessageDialog(null, tutorial);

    element = 20;
    speed = 512;
    age = 15;
    tfn = 563_435_123;
    height = 120.3f;
    weight = 56.8;
    alive = false;
    firstinitial = 'D';

    JOptionPane.showMessageDialog(null, tutorial);
}

}

Answer 1

你非常接近。您需要确保在更新值时，还要更新教程字符串。你的刺痛只会复制你最初给它的值。因此，更改原件并且副本不知道。

这应该有用。

import javax.swing.JOptionPane;

public class week02tutorial02 {

public static void main(String[] args) {
    byte element = 63 ;
    short speed = 1192 ;
    int age = 10;
    long tfn = 987_654_321 ;
    float height = 161.5f ;
    double weight = 80.4 ;
    boolean alive = true ;
    char firstinitial = 'C';

    String tutorial = "Favourite element: " +element+"\n"
        + "Running Speed: "+speed+"kph\n"
        + "Age: "+age+"\n"
        + "Tax File Number: "+tfn+"\n"
        + "Height: "+height+"cm\n"
        + "Weight: "+weight+"Kg\n"
        + "Still Alive: "+alive+"\n"
        + "First Initial: "+firstinitial+"\n";
    JOptionPane.showMessageDialog(null, tutorial);

    element = 20;
    speed = 512;
    age = 15;
    tfn = 563_435_123;
    height = 120.3f;
    weight = 56.8;
    alive = false;
    firstinitial = 'D';

    //new line to update tutorials values
    tutorial = "Favourite element: " +element+"\n"
        + "Running Speed: "+speed+"kph\n"
        + "Age: "+age+"\n"
        + "Tax File Number: "+tfn+"\n"
        + "Height: "+height+"cm\n"
        + "Weight: "+weight+"Kg\n"
        + "Still Alive: "+alive+"\n"
        + "First Initial: "+firstinitial+"\n";

    JOptionPane.showMessageDialog(null, tutorial);
}

}

Java - 变量未更新

1 个答案: