3 个 for 循环打印以下模式：

Question

我侄女在学校做作业时问我这个问题，我不知道该怎么做。

老师要求他们在 java 中使用 3 个 for 循环打印以下模式：

1******

12*****

123****

1234***

12345**

123456*

1234567

请帮忙。

谢谢！

Answer 1

这曾经是我的家庭作业代码for (int i = 1; i <= 7; i++) {&nbsp; &nbsp; for (int j = 1; j <= i; ++j) {&nbsp; &nbsp; &nbsp; &nbsp; System.out.print(j);&nbsp; &nbsp; }&nbsp; &nbsp; System.out.println("");}将会呈现1121231234123451234561234567和for (int i = 1; i <= 7; i++) {&nbsp; &nbsp; for (int k = 7 - i; k >= 1; k--) {&nbsp; &nbsp; &nbsp; &nbsp; System.out.print("*");&nbsp; &nbsp; }&nbsp; &nbsp; System.out.println("");}将会呈现*********************最终的for (int i = 1; i <= 7; i++) {&nbsp; &nbsp; for (int j = 1; j <= i; ++j) {&nbsp; &nbsp; &nbsp; &nbsp; System.out.print(j);&nbsp; &nbsp; }&nbsp; &nbsp; for (int k = 7 - i; k >= 1; k--) {&nbsp; &nbsp; &nbsp; &nbsp; System.out.print("*");&nbsp; &nbsp; }&nbsp; &nbsp; System.out.println("");}将会呈现1******12*****123****1234***12345**123456*1234567

Answer 2

public static void printPattern(int n) {&nbsp; &nbsp; &nbsp; &nbsp; for(int i=0; i<n; i++) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(int k=1; k<=i+1; k++) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.print(k);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for(int j=i+1; j<n; j++) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.print("*");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("");&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }

Answer 3

&nbsp; Are you sure question has been asked to solve by using 3 for loops?&nbsp; &nbsp; As it is better to use less loop as much as we can. Secondly there is no requirement in problem to use third loop. you can find the desired result by using two loops:&nbsp; &nbsp; public class Main&nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; public static void main(String[] args) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;for (int i = 1; i <= 7; i++) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; for (int j = 1; j <= 7; j++) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; if (j <= i) {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.print(j);&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; else&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; {&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.print("*");&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; System.out.println("\n");&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; &nbsp; &nbsp; }&nbsp; &nbsp; }&nbsp;output will be:1******12*****123****1234***12345**123456*1234567