CODEWITHSUNDEEP
javaarraysreferenceinstantiation
Cristof
Cristof

Reputation: 33

Misunderstood object instantiation in Java

I have the following code snippet for primitives array instantiation

int[] a = new int[] {10, 20, 30}

Is it possible to do the same for any Object Array instantiation ? Something like .. 

 public class MyObject {
     int a;
     char b;
 }

And then: 

 public class Main(){
     public static void main(String[] args){
         MyObject[] = new MyObject[] { {10, 'a'}, {20, 'b'}}
     }
 }

Upvotes: 1

Views: 76

Answers (4)

Lealo
Lealo

Reputation: 321

Make a contructor in your MyObject class:

public MyObject(int x, char c) {
    // comment: set them equal to the variables you put up in your MyObject class already
}

Then you can create an object in your Main class:

MyObject object1 = new MyObject(10, 'a');

Then place object1 in the array: array[0] = object1.

Or you can can store the new MyObject(10, 'a') directly into the array - but it might be a bit harder to understand if you are new to it.

Upvotes: 0

Ronak Patel
Ronak Patel

Reputation: 671

You have to declare one constructor in the class. 

public class MyObject {
   int a;
   char b;
   MyObject(int a, char b){
    this.a = a;
    this.b = b;
   }
}

After that you can initialize array like this 

MyObject[] somedamn = new MyObject[] { new MyObject(10,'a'), new MyObject(20,'b')};

Upvotes: 2

syntagma
syntagma

Reputation: 24344

Not implicitly. You would have to use constructor for the initialization of each object. Here is an example:

public class Example {

    static class MyObject {
        int a;
        char b;

        public MyObject(int a, char b) {
            this.a = a;
            this.b = b;
        }
    }

    public static void main(String[] args) {
        MyObject[] objs = new MyObject[] {new MyObject(10, 'a'), new MyObject (20, 'b')};
    }
}

Upvotes: 6

Eran
Eran

Reputation: 394016

You'll need to write the appropriate constructor in the MyObject class (which takes int and char arguments and initializes the members a and b) and then initialize the array with:

MyObject[] arr = new MyObject[] {new MyObject(10, 'a'), new MyObject (20, 'b')};

Upvotes: 3

Related Questions