CODEWITHSUNDEEP
java
romanos
romanos

Reputation: 1338

Is there any difference between ways we are declaring arrays?

And

Are there any practical differences between those?

Upvotes: 3

Views: 84

Answers (3)

Ahmet Karakaya
Ahmet Karakaya

Reputation: 10147

look at the bytecode from compiled class files, There is no difference. 

public class XFace  {

    public void test1(){
        int[] a = new int[] {1, 2, 3};
    }


    public void test2(){
        int[] a = {1, 2, 3};

    }

}

Compiled from "XFace.java"
public class XFace extends java.lang.Objec
public XFace();
  Code:
   0:   aload_0
   1:   invokespecial   #8; //Method java/
   4:   return

public void test1();
  Code:
   0:   iconst_3
   1:   newarray int
   3:   dup
   4:   iconst_0
   5:   iconst_1
   6:   iastore
   7:   dup
   8:   iconst_1
   9:   iconst_2
   10:  iastore
   11:  dup
   12:  iconst_2
   13:  iconst_3
   14:  iastore
   15:  astore_1
   16:  return

public void test2();
  Code:
   0:   iconst_3
   1:   newarray int
   3:   dup
   4:   iconst_0
   5:   iconst_1
   6:   iastore
   7:   dup
   8:   iconst_1
   9:   iconst_2
   10:  iastore
   11:  dup
   12:  iconst_2
   13:  iconst_3
   14:  iastore
   15:  astore_1
   16:  return

}

Upvotes: 0

Marko Topolnik
Marko Topolnik

Reputation: 200296

Your second form is just syntactic shorthand for the first form. They compile into exactly the same bytecode.

Upvotes: 0

Maroun
Maroun

Reputation: 96016

They are equivalent, no difference between the two.

new keyword creates an object.. and you're creating.. an array, which is an object.

See Chapter 10. Arrays:

In the Java programming language, arrays are objects (§4.3.1)...

Upvotes: 2

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