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Java

Posted by Christopher Johnson
Christopher Johnson
2,069 Points

What is the difference between Primitive and Reference type variables? What makes a variable Primitive? Java

Hi,

I understand which types are Primitive but I don't understand what makes them Primitive, I've read a book and several websites on it but I'm still confused.

Could someone help explain to me what Primitive means and what makes a variable Primitive.

Thanks in advance!

Chris

1 Answer

Kourosh Raeen
Kourosh Raeen
23,733 Points

Hi Chris - Primitive variables store the actual values, meaning that if you go to the variable's memory location you will find the value of the variable. However, reference variables store the addresses of the objects they refer to, so if you visit their memory locations you find the bits representing a way to get to an object on the heap, which is an area of memory where objects live.

Christopher Johnson
Christopher Johnson
2,069 Points

Thank you so much, I've read text books, online and asked friends and this is the best wording. Huge thank you! Can you please explain why a String isn't a Primitive variable type?

Grigorij Schleifer
Grigorij Schleifer
10,365 Points

A comment from Yin Zhu in THIS stackoverflow post says:

"int, char, float, double, etc. all have a fixed length in memory. e.g. a int have 4 bytes, thus 32bits.

but a string can have different length, it is actually an array of char"

I think it answers your second question a little bit :)

Christopher Johnson
Christopher Johnson
2,069 Points

Thanks Grigorij, I appreciate the help too!

Grigorij Schleifer
Grigorij Schleifer
10,365 Points

:thumbsup: