Printing array of char in java in matrix-like form

Question

I am writing a program to display an array of char in rows and columns(see below). But, the output of my code right now is like so:

hhhhehehehelhelhelhellhellhell

What i want to display is this:

h e l l
o w o r
l d n e
w d a y

And here's my current code:

String str = "helloworldnewday"; 

  double length = Math.sqrt(str.length());
  int x = (int) length;

  char[] ch = new char[str.length()]; 

  for (int i = 0; i < x; i++) { 
    for (int j = 1; j< x; j++){
      ch[i] = str.charAt(i); 
      System.out.print(ch);
    } 
  }

I know my code is terrible because I just began learning. Can you guys tell me what's wrong with my code? I appreciate every answer. Thank you.

[What is a debugger and how can it help me diagnose problems?](https://stackoverflow.com/q/25385173/5221149) — Andreas, Jun 30 '20 at 04:29
It is unclear how that code is supposed to print multiple lines of text, when you never call `println()`. — Andreas, Jun 30 '20 at 04:32
What is the purpose of `j` when you never use it in the code? — Andreas, Jun 30 '20 at 04:33

score 1 · Accepted Answer · answered Jun 30 '20 at 04:30

You only need one for loop over all the characters of the String. Use the modulus operator (%) to check if you need to print a new line. See the below code in action here.

String str = "helloworldnewday";
double length = Math.sqrt(str.length());
int x = (int) length;
for (int i = 0, len = str.length(); i < len; i++) {
    System.out.print(str.charAt(i) + " ");
    if (i % x == x - 1) {
        System.out.println();
    }
}

Output:

h e l l 
o w o r 
l d n e 
w d a y

Printing array of char in java in matrix-like form

1 Answers1