Ah! Something just came to mind - recursion. If a recursive function needs access to a variable, and you want the function to pass that variable to itself, then you want - and may need - a reference parameter. Otherwise, you're just allocating unnecessary memory - and may, in fact, cause a "stack overflow".

Ah! Something just came to mind - recursion. If a recursive function needs access to a variable, and you want the function to pass that variable to itself, then you want - and may need - a reference parameter. Otherwise, you're just allocating unnecessary memory - and may, in fact, cause a "stack overflow".

Edit: Some people have noted that pointers exist. Be that as it may, reference variables are sometimes preferable simply because they render referencing and dereferencing unnecessary.