Create array of inner class object in a different class

Question

Consider the following nested classes.

class Outerclass {

    class innerclass {

    }

}

 class util {

 //how to declare an array of innerclass objects here?
}

See http://stackoverflow.com/questions/70324/java-inner-class-and-static-nested-class — link64, Jan 23 '14 at 05:10

Rahul · Accepted Answer · 2014-01-23T05:15:13.613

13

You can declare an array of innerclass objects like this.

class util {
    Outerclass.innerclass[] inner = new Outerclass.innerclass[10];
}

And to instantiate them you can do something like this inside the util class.

void test() {
    Outerclass outer = new Outerclass();
    inner[0] = outer.new innerclass();
}

edited Jan 23 '14 at 05:15

answered Jan 23 '14 at 05:09

Rahul

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when you say myclass[] a = new myclass[5]; we don't intialize again right? So, when we say new Outerclass.innerclass[10]; isn't that enough to allocate memory for the array? Why do we have to do Outerclass outer = new Outerclass(); inner[0] = outer.new innerclass(); again? – Namratha Jan 23 '14 at 05:59
1

You've created an array of `innerclass`. Won't you have to initialize each element in the array? If it was a primitive data type like `int`, all the elements would be filled with `0` by default. But in this case, it'd be `null`. All the array elements needs to be initialized. You've just declared and initialized the an array, but have not initialized the elements in the array. – Rahul Jan 23 '14 at 06:09
won't new Outerclass.innerclass[10]; call the constructors of both the outer and inner classes? If the constructor of the inner class is called then we wouldn't have to initialize it by ourselves. – Namratha Jan 23 '14 at 06:30

score 2 · Answer 2 · edited Apr 02 '20 at 06:24

OuterClass outerObject = new OuterClass();
OuterClass.InnerClass innerArray[] = new OuterClass.InnerClass[3];
// Creating Objects of Inner Class
OuterClass.InnerClass innerObject1 = outerObject.new InnerClass();
OuterClass.InnerClass innerObject2 = outerObject.new InnerClass();
OuterClass.InnerClass innerObject3 = outerObject.new InnerClass();
// Adding the Objects to the Array
innerArray[0] = innerObject1;
innerArray[1] = innerObject2;
innerArray[2] = innerObject3;

Create array of inner class object in a different class

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