使用for打印三角形,平行四边形和菱形

        //三角形
        for (int i = 1; i <=  5; i++) {
            for (int k = 5; k >=i; k--) {
                System.out.print(" ");
            }
            for (int j = 1; j <= i; j++) {
                System.out.print("*");
            }
            for (int o = 1; o < i; o++) {
                System.out.print("*");
            }
            System.out.println();
        }
        //平行四边形
        for (int i = 1; i <= 5; i++) {
            for (int k = 5; k >=i; k--) {
                System.out.print(" ");
            }
            for (int j = 1; j <= i ; j++) {
                System.out.print("*");
            }
            for (int k = 5; k >=i; k--) {
                System.out.print("*");
            }
            System.out.println();
        }
        //菱形
        for (int i = 1; i <= 5; i++) {
            for (int k = 5; k >=i; k--) {
                System.out.print(" ");
            }
            for (int k = 1; k <=i; k++) {
                System.out.print("*");
            }
            for (int k = 1; k <i; k++) {
                System.out.print("*");
            }
            System.out.println();
        }
        for (int i = 1; i <= 4 ; i++) {
            for (int k = 0; k <=i; k++) {
                System.out.print(" ");
            }
            for (int k = 4; k >=i; k--) {
                System.out.print("*");
            }
            for (int k = 4; k >i; k--) {
                System.out.print("*");
            }
            System.out.println();
        }

使用for打印三角形,平行四边形和菱形

原文：https://www.cnblogs.com/ShuaiStudy/p/13948699.html