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Java(五、類和對象中的例題)

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一、方法中的參數為數值型的(int)

import java.util.Scanner;
public class ScoreCalc {
    public void calc(int num1,int num2,int num3){
        int sum = num1 + num2 +num3;
        double avg = sum / 3;
        System.out.println("總成績:"+sum);
        System.out.println("平均分:"+avg);
    }
    public static void main(String[] args) {
        Scanner input 
= new Scanner(System.in); System.out.println("請輸入Java的成績:"); int num1 = input.nextInt(); System.out.println("請輸入C的成績:"); int num2 = input.nextInt(); System.out.println("請輸入DB的成績:"); int num3 = input.nextInt(); ScoreCalc calc = new ScoreCalc();
calc.calc(num1, num2, num3);
     input.close(); } }

運行圖:

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二、方法中的參數為字符串數組的(String[])

import java.util.Arrays;
public class SortName {
    public String[] sortName(String[] unOrderArr){
        Arrays.sort(unOrderArr);
        return unOrderArr;
    }
}
import java.util.Arrays;
import
java.util.Scanner; public class SortNameTest { public static void main(String[] args) { String name[] = new String[5]; Scanner scanner = new Scanner(System.in); System.out.println("請輸入學員名單:"); for (int i = 0; i < 5; i++) { name[i] = scanner.next(); } SortName sortName = new SortName(); String[] orderArr = sortName.sortName(name); System.out.println(Arrays.toString(orderArr)); scanner.close(); } }

運行圖:

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三、方法中的參數為對象的(Student student)

public class Student {
    double chinese;
    double math;
    double english;
    public Student(double chinese,double math,double english){
        this.chinese = chinese;
        this.math = math;
        this.english = english;
    }
}
public class StudentCalc {
    public double calc(Student zhangSan){
        double avg = (zhangSan.chinese + zhangSan.math + zhangSan.english) / 3;
        return avg;
    }
}
import java.util.Scanner;
public class StudentTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("請輸入語文成績:");
        double chinese = scanner.nextDouble();
        System.out.println("請輸入數學成績:");
        double math = scanner.nextDouble();
        System.out.println("請輸入英語成績:");
        double english = scanner.nextDouble();
        Student zhangSan = new Student(chinese, math,english);
        StudentCalc scoreAvg = new StudentCalc();
        double avg = scoreAvg.calc(zhangSan);
        System.out.println("三門課的平均分數是:"+avg);
        scanner.close();
    }
}

運行圖:

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四、方法中的參數為對象數組的(Student[] s)

public class Student {
    String name;
    int age;
    double height;
    public Student(String name,int age,double height){
        this.name = name;
        this.age = age;
        this.height = height;
    }
}
public class StudentManager {
    public double heightAvg(Student[] s){
        double sum = 0;
        for (int i = 0; i < s.length; i++) {
            sum += s[i].height;
        }
        return sum/s.length;
    }
}
import java.util.Scanner;
public class StudentManagerTest {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Student students[] = new Student[2];
        for (int i = 0; i < students.length; i++) {
            System.out.println("請輸入第"+(i+1)+"個學員的姓名:");
            String name = scanner.next();
            System.out.println("請輸入第"+(i+1)+"個學員的年齡:");
            int age = scanner.nextInt();
            System.out.println("請輸入第"+(i+1)+"個學員的身高:");
            double height = scanner.nextDouble();
            Student student = new Student(name,age,height);
            students[i] = student;
        }
        StudentManager manager = new StudentManager();
        double avg = manager.heightAvg(students);
        System.out.println("平均身高為:"+avg);
        scanner.close();
    }
}

運行圖:

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Java(五、類和對象中的例題)