Comparing a 2 dimensional array to a single dimensional array in Java

Question

Does anyone know why this doesn't compile?

public class ArrayCompare{

   public static void main (String []args){

      String words= "Hello this is a test";

      String delimiter=" ";
      String [] blocker=words.split(delimiter);

      String [][] grid= new String [100][100];

      grid[0]="Hello";

           if (grid[0].equals(blocker[0])){
                 System.out.print("Done!");
   }
        }
             }

I would like to perform this function of comparison using a 2 dimensional array. I am a newbie! Please help if you can. Thanks in advance!

Answer 1

Try this:

grid[0][0]="Hello";

grid is a two-dimensional array. For the same reason, you need to do this:

if (grid[0][0].equals(blocker[0]))

Answer 2

It won't compile because grid[0] is not String type. It is String[] (Array) type. Variable grid[0] is actually pointing to a String[100] array.

You are attempting to assign a string "Hello" to an array by

grid[0]="Hello"; statement.

If you want to assign a string to a location in grid , you must provide two index(s) - following is legal:

grid[0][0]="Hello";

May I suggest using eclipse or BlueJ to edit your Java code? so that such basic errors are shown on real-time and explained well?

Answer 3

grid[0] is a String[] type, not a String . So your code should be like this

grid[0] = new String[100];
grid[0][0] = "Hello";
if (grid[0][0].equals(bloker[0])) {
    //your logic...
}

Answer 4

String [][] grid= new String [100][100];

  grid[0]="Hello";

There's your problem. You are trying to assign a string to a string array. Think of a 2d array as an array of arrays.

You probably want something like

grid[0][0]="Hello!";

Answer 5

grid is 2d array. you can't do like d[0] = "Hello". So, if you want to assign value at 0 position

d[0][0] = "Hello";

 if (grid[0][0].equals(blocker[0])){
System.out.print("Done!");
 }

Answer 6

First thing you can't assign value to the element of the multi dimensional array using single index

grid[0]="Hello";
you need to specify both the indices like grid[0][0] = "Hello" this will set the 0th element of 0th row to Hello

Likewise while compairing if (grid[0].equals(blocker[0])){ System.out.print("Done!"); you have to pass the same indices here (You cannot compare a String to a Array Object) if (grid[0][0].equals(blocker[0])){ System.out.print("Done!");