이자바 5장(참조 타입) 확인문제

- 7번: 주어진 배열의 항목에서 최대값을 구하시오.

package ch5;

public class exercise7 {

	public static void main(String[] args) {

		int max = 0;
		int[] array = { 1, 5, 3, 8, 2 };

		for (int i = 0; i < array.length; i++) {
			if (array[i] > max) {
				max = array[i];
			}
		}

		System.out.println(max);

	}

}

 

 

- 8번: 주어진 배열의 전체 항목의 합과 평균값을 구하시오.

package ch5;

public class exercise8 {

	public static void main(String[] args) {

		int[][] array = { { 95, 86 }, { 83, 92, 96 }, { 78, 83, 93, 87, 88 } };

		int sum = 0;
		double avg = 0.0;
		double count = 0.0;

		for (int i = 0; i < array.length; i++) {
			for (int j = 0; j < array[i].length; j++) {
				sum += array[i][j];
			}
			count += array[i].length;
		}

		avg = sum / count;

		System.out.println(sum);
		System.out.println(avg);

	}

}

 

 

- 9번: 코드를 완성하시오.

package ch5;

import java.util.Scanner;

public class exercise9 {

	public static void main(String[] args) {

		boolean run = true;
		int studentNum = 0;
		int[] scores = null;
		Scanner scanner = new Scanner(System.in);

		while (run) {
			System.out.println("--------------------");
			System.out.println("1. 학생수 | 2. 점수입력 | 3. 점수리스트 | 4. 분석 | 5. 종료");
			System.out.println("--------------------");
			System.out.print("선택> ");

			int selectNo = scanner.nextInt();

			if (selectNo == 1) {
				System.out.print("학생수> ");
				studentNum = scanner.nextInt();
				scores = new int[studentNum];
			} else if (selectNo == 2) {
				for (int i = 0; i < studentNum; i++) {
					System.out.print("scores[" + i + "]> ");
					scores[i] = scanner.nextInt();
				}
			} else if (selectNo == 3) {
				for (int j = 0; j < studentNum; j++) {
					System.out.println("scores[" + j + "]> " + scores[j]);
				}
			} else if (selectNo == 4) {
				int highst = 0;
				double sum = 0.0;
				double avg = 0.0;
				for (int k = 0; k < studentNum; k++) {
					if (scores[k] > highst) {
						highst = scores[k];
					}
				}
				for (int k = 0; k < studentNum; k++) {
					sum += scores[k];
				}
				avg = sum / studentNum;
				System.out.println("최고점수: " + highst);
				System.out.println("평균점수: " + avg);
			} else if (selectNo == 5) {
				run = false;
			}
		}

		System.out.println("프로그램 종료");

	}

}