import java.util.Scanner;

class L15 {
	public static void main(String[] args) {

		int[] arr = { 10, 20, 30};

		int[] arr2 = new int[10];
		int len = arr2.length;
		//set the value of the first element to 7
		arr2[0] = 7;
		//arr[10] = 13;	
		//arr[-3] = 5;

		int x = arr2[3];
		System.out.println("x: " + x);

		for(int y : arr2) {
			System.out.print(y + " "); 
		}
		System.out.println();

		for(int i = 0; i < len; i++) {
			int y = arr2[i];
			System.out.print(y + " "); 
		}
		System.out.println();

		// System.out.printf
		System.out.printf("first: %d, second: %d\n", arr2[0], arr2[1]);

		String name = "Betty";
		char initial = 'B';
		double height = 65.3;
		System.out.printf("%s %c height: %.1f\n", name, initial, height);

		System.out.println(name + " " + initial + " height: " + height);

		// 2D arrays
		int[][] matrix = {{1,2,3}, {4,5,6},{7,8,9,10}}; 
		
		for(int i = 0; i < matrix.length; i++) {
			int[] a = matrix[i];		
			for(int j = 0; j < a.length; j++) {
				System.out.print(a[j] + " ");
			}
			System.out.println();
		}
	
		for(int[] a: matrix) {
			for(int elm: a) {
				System.out.print(elm + " ");
			}
			System.out.println();
		}

		int[][] matrix2 = new int[3][4];

		for(int i = 0; i < matrix2.length; i++) {
			for(int j = 0; j < matrix2[i].length; j++) {
				matrix2[i][j] = -1;
			}
		} 

		for(int[] a: matrix2) {
			for(int elm: a) {
				System.out.print(elm + " ");
			}
			System.out.println();
		}
	}
} // End of class