\r\n 换行 \t 缩进

正三角

打印展示

实现代码

for (int i = 1; i < 10; i++) {
    for (int j = 1; j <= i; j++) System.out.print(j + " * " + i + " = " + (i * j) + (i == j ? "\r\n" : "\t"));
}

倒三角

打印展示

实现代码

for (int i = 9; i > 0; i--) {
    for (int j = 1; j <= i; j++) System.out.print(j + " * " + i + " = " + (i * j) + (i == j ? "\r\n" : "\t"));
}

打印展示

代码实现

for (int i = 1; i < 10; i++) {
     for (int j = i; j < 10; j++) System.out.print(i + " * " + j + " = " + (i * j) + (j == 9 ? "\r\n" : "\t"));
}

正方形

打印展示

实现代码

for (int i = 1; i < 10; i++) {
    for (int j = 1; j < 10; j++) System.out.print(i + " * " + j + " = " + (i * j) + (j == 9 ? "\r\n" : "\t"));
}

倒方形

Math.min 获取两个数字中最小的数字 Math.max 获取两个数字中最大的数字

打印展示

实现代码

for (int i = 9; i > 0; i--) {
    for (int j = 1; j < 10; j++) System.out.print(Math.min(i, j) + " * " + Math.max(i, j) + " = " + (i * j) + (j == 9 ? "\r\n" : "\t"));
}