[Solved]: Equality testing of arrays and integers in a procedural language

Problem Detail: 

In terms of references and their implementation on the heap and the stack, how is equality testing for arrays different from that for integers?

This is to do with Java programming, if you have a stack and a heap, would equality testing for example j == i be the same for arrays and for integers? I understand that arrays, are stored in the heap and the stack, as it holds bulks of data, but integers are only stored in the stack and referenced in the heap.

I understand for equality testing j==i (variables) the stack pointer will point to the same location.

I'm confused on how j==i would be different for array and integers.

Could someone explain?

Asked By : Xabi

Answered By : Dave Clarke

Integers are stored in one word of memory and there is a primitive machine code instruction for testing their equality. Most programming languages lift this instruction to the syntax, as with i == j in Java (where i and j are of type int).

Arrays are stored in multiple contiguous words in memory. In order to test the equality of two arrays, the program needs to iterate through each pair of memory locations and test the equality of the elements stored in them.

Some programming languages hide the distinction between these to operations by allowing the syntax == to be used for testing the equality of two arrays (one can do this in C++, for instance, or Ruby). Other programming languages, such as Java, do not.

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Question Source : http://cs.stackexchange.com/questions/1919

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