Topic: ClassCastException when casting Array from Subclass to Super Class

ClassCastException when casting Array from Subclass to Super Class

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Posted By: S_Luk
Posted On: Tuesday, February 21, 2006 01:19 AM

I am getting ClassCastException with trying to do the following A SuperClass which cannot be changed. A SubClass which extends SuperClass. class SomeOtherClass { public SubClass[] getSubArray() { SuperClass[] superArray = this.getSuperArray(); SubClass[] subArray = new SubClass[superArray.length]; for(int i = 0; i < superArray.length; i++) { SuperClass superObj = new SubClass(); superObj = superArray[i]; subArray[i] = (SubClass) superObj; } } } A ClassCastException is thrown at subArray[i] = (SubClass) superObj; Any other way of doing casting of array between Sup More>>

I am getting ClassCastException with trying to do the following

A SuperClass which cannot be changed.

A SubClass which extends SuperClass.

class SomeOtherClass {

			

			public SubClass[] getSubArray() {
			

			SuperClass[] superArray = this.getSuperArray();
			

			SubClass[] subArray = new SubClass[superArray.length];
			

			for(int i = 0; i
			< superArray.length; i++) {
			

			SuperClass superObj = new SubClass();
			

			superObj = superArray[i];
			

			subArray[i] = (SubClass) superObj;
			

			}
			

			}

}

A ClassCastException is thrown at subArray[i] = (SubClass) superObj;

Any other way of doing casting of array between Super and Sub Class? Thanks.

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Re: ClassCastException when casting Array from Subclass to Super Class

Posted By: ankush_purwar
Posted On: Tuesday, February 21, 2006 01:26 PM

It seems there is some problem with your code.

SuperClass superObj = new SubClass();
superObj = superArray[i]; /* This line will loose the object of subclass that you hava create in first step. */
subArray[i] = (SubClass) superObj;

I hope you understands now

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Re: ClassCastException when casting Array from Subclass to Super Class

Posted By: Almagest_FUTT
Posted On: Tuesday, February 21, 2006 09:02 AM

You have Objects in your superArray that are not instances of SubClass. You can't cast in this case.

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