Question

我的程序需要帮助。我需要在两个（）中使用变量“three”，“four”但我不知道如何。请帮忙。

public class Main {

public static void main(String[] args) {
    one()
}

public static void one(){
    Integer three;
    Integer four;
    Integer five;
    three = 3;
    four = 4;
    two();


}
public static void two(){
    five = three + four;
    System.out.println(five);
}



}

Answer 1

将它们设为类变量，因此将它们置于方法之外：

static Integer three;
static Integer four;
static Integer five;

public static void one(){
    three = 3;
    four = 4;
    two();    
}

将one()更改为one();

或者您可以为two()方法制作参数：

public static void one(){
    Integer three;
    Integer four;
    three = 3;
    four = 4;
    two(three, four); // add parameters here
}
public static void two(Integer three, Integer four){
    Integer five; // declare five here
    five = three + four;
    System.out.println(five);
}

Answer 2

“我需要在两个（）中使用变量”三“，”四“，但我不知道如何。”

将它们作为参数传递给方法

public static void two(Integer four, Integer three){
    int five = three + four;
    System.out.println(five);
}

像这样称呼

two(four, three);

public class Main {

    public static void main(String[] args) {
        one();
    }

    public static void one() {
        Integer three;
        Integer four;
        three = 3;
        four = 4;
        two(four, three);

    }

    public static void two(Integer four, Integer three) {
        int five = three + four;
        System.out.println(five);
    }
}

输出：7

Answer 3

您可以尝试将它们声明为类中的字段：

public class Main {
    private static int three;
    private static int four;
    private static int five;
    ...
}

如果这样做，则不必在方法中再次声明它们：

public static void one(){
    three = 3;
    four = 4;
    five = two();
}

或者您可以尝试将它们作为参数传递给two()方法，并返回一个值：

public static void two(int three, int four){
    return three + four;
}

然后在one()方法中：

public static void one(){
    Integer three;
    Integer four;
    Integer five;
    three = 3;
    four = 4;
    five = two(three, four); // Assign the value returned by the 'two()' method
}

您选择的方式取决于您要做的事情。所以你必须选择一个更符合你情况的那个。

Answer 4

您有两种选择。

在班级将three和four声明为static，让five成为two()的返回结果：

public class Main {
    static Integer three;
    static Integer four;

    // more code
    public static void one() {
        three = 3;
        four = 4;
        Integer five = two();
        System.out.println(five);
    }

    public static Integer two() {
        return three + four;
    }
}

传入变量（最好删除静态声明，强制您使用方法one()创建对象的新实例）：

public class Main {
    public void one() {
        Integer five = two(3, 4);
        System.out.println(five);
    }
    public Integer two(Integer three, Integer four) {
        return three + four;
    }
    public static void main(String[] args) {
        new Main().one();
    }
}

Answer 5

你可能想要：

public static void one(){
    int five = two(3,4);
}
public static int two(int three, int four){
    int five = three + four;
    System.out.println(five);
    return five;
}

Answer 6

class F1() {
  int a;
  int b;
  void execute() {
    a = 1;
    b = 2;
    two(this);
  };
}

void two(F1 f1) {
  int c = f1.a + f1.b;
}

或在全局范围内移动局部变量声明

static int a;
void f1() {}
void f2() {};

我如何在其他函数中使用变量

6 个答案: