Adding two or more nested for loops in a JAVA programme

Question

I am just a beginner in JAVA and while doing a class tutorial I got this problem. This is the output I should get:

  1    
 123
12345
 123
  1

I wrote this code and it gives a compilation error at line 16 saying that "for(int k=1; k<=5-i; k++)" is an unreachable statement.

 public class CaseThree{ public static void main (String[] args){ for(int a=1; a<=3; a++){ for(int b=1; b<=3-a; b++){ System.out.print(" "); } for(int c=1; c<=2*a-1; c++){ System.out.print(c); } System.out.println(); } for(int i=1; i<=2; i++){ for(int j=1;; j++){ System.out.print(" "); } for(int k=1; k<=5-2*i; k++){ System.out.print(k); } System.out.println(); } } } 

What is wrong with this code? (Our lecturer told us to use two separate nested for loops.)

Answer 1

Look at the code right before the statement that the compiler says that is impossible to reach

for(int j=1;; j++){
    System.out.print(" ");
}

the validation expression is empty, hence this is an infinite loop which explain the compilation error.

Answer 2

for（int j = 1; \\这是什么？\\; j ++）

Answer 3

第13行的无限循环。无需条件检查即可结束循环。而且，对于此类输出，您不需要那么多的for循环。