Java 定义一个3行4列的二维数组，逐个从键盘输入值，将左下三角的值清0

package cn.zhang;

import java.util.Scanner;

public class Subject001 {
	/*
	 * 定义一个3行4列的二维数组，逐个从键盘输入值，将左下三角的值清0
	 */
	public static void main(String[] args) {

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

		Scanner sc = new Scanner(System.in);

		for (int i = 0; i < nums.length; i++) {
			for (int j = 0; j < nums[i].length; j++) {
				System.out.println("请输入二维数组里第" + (i + 1) + "个元素里的第" + (j + 1) + "个值：");
				nums[i][j] = sc.nextInt();
			}
		}
		System.out.println("您输入的二维数组是：");
		for (int[] is : nums) {
			for (int i : is) {
				System.out.print(i + "\t");
			}
			System.out.println();
		}
		for (int i = 0; i < nums.length; i++) {
			for (int j = 0; j < nums[i].length; j++) {
				if ((i == 1 && j == 0) || (i == 2 && j == 0) || (i == 2 && j == 1)) {
					nums[i][j] = 0;
				}
			}
		}
		System.out.println("\n左下三角的值清0后数组是：");
		for (int[] is : nums) {
			for (int i : is) {
				System.out.print(i + "\t");
			}
			System.out.println();
		}
		sc.close();
	}
}

结果：