使用嵌套循环绘制网格

Question

I am trying to draw a grid that looks like this:

1

12

123

1234

12345

123456

1234567

12345678

123456789

Here is my code:

public class shape { 
    public static void main(String[] args){

        int number = 1, newNumber, zMax = 1;
        String numString = "1";

        for (int i = 1; i <= 9; i++){

            for (int z = 0; z < zMax; z++){

                System.out.print(numString);
                number = number + 1;
                numString += Integer.toString(number);
            }
            System.out.println("");
            if (zMax <= 9)
                zMax++; 
        }
    }
}

It prints out something like this:

1

12123

121231234

12123123412345

etc

It is on the right track but I can't figure out what is going wrong... please help!

Answer 1

EDIT: Miss-understood the question, corrected it.

The reason your numbers repeat is your second loop. you either need to reinitialize numstring or reuse the old one and only add the new number.

public class shape { public static void main(String[] args){

    String numString = "";

    for (int i = 1; i <= 9; i++){
        numstring = numstring + i;
        System.out.println(numstring);
    } 

}

Answer 2

int start = 1;
int max = 10;
for(int i = 1; i < max; i++){
  for(int j = 1; j <= i; j++){
    System.out.print(j);
  }
  System.out.println("");
}