Does C Pass Objects by Value or by Reference?

Does C Pass Objects by Value or Reference?

Question:

In C , there seems to be some ambiguity regarding whether objects are passed by value or reference to functions. While simple data types like integers and floats are passed by value, it's unclear what happens with arrays and objects. Does C pass objects by value or reference?

Answer:

In C , argument passing is primarily by value, meaning that a copy of the argument is created and passed to the function. However, there are ways to pass arguments by reference, allowing the function to directly modify the original variable.

Specifically:

• In void foo(type arg), the argument arg is passed by value. This applies to simple types, pointers, and class types. In the case of arrays, a pointer to the first element is passed, not a copy of the array.
• In void foo(type& arg), the argument arg is passed by reference. This allows the function to modify the original variable.
• For arrays, if the array size is known at compile time, it can be passed by reference using void foo(type (&arg)[10]).

Therefore, in C , objects are generally passed by value unless explicitly specified as pass-by-reference through the use of the '&' reference operator.

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