Global and Local Variables (OCR A-Level Computer Science): Flashcards

Named storage locations in memory used to hold data

Where a variable can be accessed within a program

Variables declared outside any function, class, or block

Accessible from any part of the program

Exist for the entire duration of the program

Variables declared within a function, class, or block

Accessible only within the block/function where defined

Exists only while the function or block is executing

Global occupy memory throughout; local memory freed after use

Useful for data accessed & modified by multiple functions

Accidental modification can lead to unintended behaviour

Memory allocated & freed dynamically, reducing consumption

Cannot be accessed outside their defining function or block

Local variable with same name as a global variable

Pass it as a parameter to functions that need it