CODEWITHSUNDEEP
javavariablesparameter-passing
jSeesFor3ver
jSeesFor3ver

Reputation: 83

Java passing of parameter

Can someone please explain in a little detail to me why this code prints 2?

import java.util.*;

public class TestCode2 {
   public static void main(String[] args) {
      int[][] array = {{1,2,3,4}, {5,6,7,8}};
      System.out.println(m1(array)[0]);
     // System.out.println(m2(array)[1]);
   }

   public static int[] m1(int[][] m) {
      int[] result = new int[2];
      result[0] = m.length;
      result[1] = m[0].length;
      return result;
   }
}

Upvotes: 0

Views: 67

Answers (3)

Raúl
Raúl

Reputation: 1552

m1() is taking 2D array as i/p & returning a (1D) array with first element as length of the i/p array, which - in this case is 2; Hence 2.

Upvotes: 1

Alexis C.
Alexis C.

Reputation: 93842

    int[][] array = {{1,2,3,4}, {5,6,7,8}};
=>  int[][] array = {arrayOne, arrayTwo};

The length of array is 2 because it's just a bi-dimensionnal array which contains 2 sub arrays (which have both a length of 4).

So 

   array.length = 2;
   array[0].length = length of arrayOne (i.e: length of {1,2,3,4}) = 4
   array[1].length = length of arrayTwo (i.e: length of {5,6,7,8}) = 4

To summarize :

public static int[] m1(int[][] m) {
      int[] result = new int[2];
      result[0] = m.length; //m.length = 2
      result[1] = m[0].length; //m[0].length = length of {1,2,3,4} = 4
      return result; //{2,4}
   }

Then you just print the first element of this array returned, i.e 2.

Upvotes: 3

Nawed Shaikh
Nawed Shaikh

Reputation: 419

This is a 2d array so : when you do like this : int [][] array = {{1,2,3,4},{5,6,7,8}} int a=array.length; \ i.e a=2 this is because the array treats the 2 sets as its element means {1,2,3,4} and {5,6,7,8} are considered as single element sorry for wrong format as i am using mobile

Upvotes: 1

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