1208JAVA -MultiArray01

package des08;

 

import java.util.Arrays;

 

//다차원 배열p190

//2차원 배열 멀티어레이 = 배열 속에 배열이 있습니다.

//index,length

public class MultiArray01 {

 

public static void main(String[] args) {

 

int numbers[] = new int[5];

int numbers2[] = new int[] { 10, 20, 30, 40, 50 };

int numbers3[] = { 10, 20, 30, 40, 50 };

 

int numbers4[][] = new int[5][5]; // 25

 

int numbers5[][] = new int[2][3];// 6

 

// 값대입

numbers4[0][0] = 15;

numbers4[0][1] = 25;

numbers4[0][2] = 30;

numbers4[0][3] = 35;

numbers4[0][4] = 40;

// numbers4[0][5]=40;// ?

 

numbers4[1][0] = 17;

numbers4[1][1] = 27;

numbers4[1][2] = 37;

numbers4[1][3] = 47;

numbers4[1][4] = 57;

// numbers5[1][5] = 67;

 

// numbers4의 모든 값을 출력하는 for문을 만들어주세요.

System.out.println("==numbers4=========================");

 

for (int i = 0; i < numbers4.length; i++) {

for (int j = 0; j < numbers4[i].length; j++) {

System.out.print(numbers4[i][j] + ", ");

 

}

System.out.println("");

}

==numbers4=========================

15, 25, 30, 35, 40,

17, 27, 37, 47, 57,

0, 0, 0, 0, 0,

0, 0, 0, 0, 0,

0, 0, 0, 0, 0,

 

 

*Math.random()으로 출력하기

int numbers4[][] = new int[5][5];

 

for (int i = 0; i < numbers4.length; i++) {

for (int j = 0; j < numbers4[i].length; j++) {

numbers4[i][j] = (int) (Math.random() * 25 + 1);

System.out.print(numbers4[i][j] + ",");

}

System.out.println("\n");

}

 

12,21,15,4,12,

 

21,9,16,3,21,

 

8,8,7,23,9,

 

5,11,16,5,21,

 

13,21,16,1,18,

 

 

 

System.out.println("===========================");

// numbers5 --> 2*3

// System.out.println(numbers5.length);//2

// System.out.println(numbers5[0].length);//3

for (int i = 0; i < numbers5.length; i++) {// 2

for (int j = 0; j < numbers5[i].length; j++) {// 3

System.out.print(numbers5[i][j] + ",");

}

System.out.println("");

}

===========================

0,0,0,

0,0,0,

 

int number5[][]=new int[2][3];

// for (int i = 0; i < number5.length; i++) {

// for (int j = 0; j < number5[i].length; j++) {

// System.out.print(number5[i][j]);

// }System.out.println("");

// }

 

for (int i = 0; i < number5.length; i++) {

for (int j = 0; j < number5[i].length; j++) {

number5[i][j]=(int)(Math.random()*6+1);

System.out.print(number5[i][j]);

}System.out.println("");

 

}

424

542

 

 

System.out.println("===========================");

int numbers6[][] = new int[4][2];

for (int i = 0; i < numbers6.length; i++) {

for (int j = 0; j < numbers6[i].length; j++) {

System.out.print(numbers6[i][j] + ",");

}

 

System.out.println("");

}

===========================

0,0,

0,0,

0,0,

0,0,

 

 

 

System.out.println("===========================");

 

int scores[][] = new int[2][3];

// 1~6까지 저장해주세요.

scores[0][0] = 1;

scores[0][1] = 2;

scores[0][2] = 3;

 

scores[1][0] = 4;

scores[1][1] = 5;

scores[1][2] = 6;

 

int number = 1;

for (int i = 0; i < scores.length; i++) {

for (int j = 0; j < scores.length; j++) {

if (i == 0) {

scores[i][j] = number++;

}

}

// System.out.println(Arrays.toString(scores));//[[I@515f550a, [I@626b2d4a]

}

for (int[] is : scores) {

System.out.println(Arrays.toString(is));

 

}

 

System.out.println("==deepToString=========================");

System.out.println(Arrays.deepToString(scores));

===========================

[1, 2, 3]

[4, 5, 6]

 

==deepToString=========================

[[1, 2, 3], [4, 5, 6]]

 

 

*Arrays.deepToString()

다차원 배열의 내용을 문자열로 변환하여 반환하는 메서드

 

 

System.out.println("===========================");

 

// 배열

int arr01[] = { 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 };

int arr02[][] = { { 10, 20, 30 }, { 40, 50, 60 } };// arr02[2][3]

 

// 중첩 for문으로 찍어주세요.

 

for (int i = 0; i < arr02.length; i++) {

for (int j = 0; j < arr02.length; j++) {

}

} //중괄호 2개 를 나와야

한다.

System.out.println(Arrays.deepToString(arr02));

 

System.out.println("*******************");

 

for (int i = 0; i < arr02.length; i++) {

for (int j = 0; j < arr02[i].length; j++) {

System.out.print(arr02[i][j] + ",");

}

}

System.out.println("'");

}

 

}

===========================

[[10, 20, 30], [40, 50, 60]]

*******************

10,20,30,40,50,60,'