Java打印输出99乘法表、三角形、菱形

1、使用for循环打印输出99乘法表，如下图所示。public class Test { public static void main(String[] args) { for(int i = 1;i <= 9;i++) { for(int j = 1;j <= i;j++) { System.out.print(i + "*" + j + "=" + i*j + "\t"); } System.out.println(); } }}

2、使用for循环打印输出三角形public class Test { public static void main(String[] args) { //正三角 for(int i = 1;i <= 5;i++) { for(int j = 1;j <= i;j++) { System.out.print("* "); } System.out.println(); } //倒三角 for(int i = 6;i >= 1;i--) { for(int j = 1;j <= i;j++) { System.out.print("* "); } System.out.println(); } }}

3、使用for循环打印输出菱形public class Test { public static 箪滹埘麽void main(String[] args像粜杵泳) { for (int i = 6; i >= 1;i--) { for (int j = 1;j < i;j++) { System.out.print(" "); } for (int k = 1;k <= 7-i; k++){ System.out.print("* "); } System.out.println(); } for (int i = 1; i <= 6; i++) { for (int j = 1; j <= i; j++) { System.out.print(" "); } for (int k = 6-i; k >= 1; k--) { System.out.print("* "); } System.out.println(); } }}

4、使用for循环打印输出圆形public class Round { public static void main(String[] args) { int r = 10; //半径 for (int y = 0; y <= 2 * r; y += 2) { long x = Math.round(r - Math.sqrt(2 * r * y - y * y)); long longLength = 2 * (r - x); for (int i = 0; i <= x; i++) { System.out.print(' '); } System.out.print('*'); for (int j = 0; j <= longLength; j++) { System.out.print(' '); } System.out.println('*'); } }}