スッキリわかるJava入門 第4章 配列（練習問題）

• 練習4-1

package sample;

public class JavaR04_01 {
    public static void main (String[] args) {
        int[] points = new int[4];
        double[] weights = new double[5];
        boolean[] answers = new boolean[3];
        String[] names = new String[3];
    }
}

• 練習4-2

package sample;

public class JavaR04_02 {
    public static void main (String[] args) {
        // ①
        // 通常
        int[] moneyList = new int[3];
        moneyList[0] = 121902;
        moneyList[1] = 8302;
        moneyList[2] = 5100;

        // 省略記法
        int[] moneyList1 = new int[]{121902, 8302, 5100};

        // 省略記法
        int[] moneyList2 = {121902, 8302, 5100};


        // ②
        // for文
        System.out.println("for文");
        for (int i = 0 ; i < moneyList.length ; i++) {
            System.out.println(moneyList[i]);
        }

        // ③
        // 拡張for文
        System.out.println("拡張for文");
        for (int money : moneyList) {
            System.out.println(money);
        }
    }
}

• 練習4-3

package sample;

public class JavaR04_04 {
    public static void main(String[] args) {
        // ①
        int[] numbers = {3, 4, 9};

        // ②
        System.out.println("1桁の数字を入力してください");

        // ③
        java.util.Scanner scanner = new java.util.Scanner(System.in);
        int input = scanner.nextInt();
        scanner.close();

        // ④
        for (int number : numbers) {
            if(number == input) {
                System.out.println("アタリ！");
            }
        }
    }
}