What are the Different Uses of the Ampersand (&) Operator in C ?

What's the Purpose of the Ampersand (&) Operator in C ?

The ampersand (&) symbol has multiple roles in C . Here are its main functions:

1. Address-of operator:

• &x yields the memory address of variable x.
• This is often used to assign pointers or pass variables by reference to functions.

2. Reference operator (declaration):

• int& r = k; creates a reference variable r that aliases variable k.
• Any changes made through r will also be reflected in k.

3. Reference operator (argument passing):

• void foo(CDummy& x); passes x by reference.
• This allows the function to modify the original variable directly, avoiding copying for performance reasons.

4. Bitwise logical AND operator:

• x & y performs bitwise logical AND on integers x and y, resulting in a value where each bit is set to 1 only if both corresponding bits in x and y are set to 1.

In the provided code snippet:

• CDummy& param declares a reference parameter in the isitme method.
• ¶m == this compares the memory address of param (pointing to the passed object) with the current object's address (this).
• This returns true only if param references the current object, effectively comparing object identity.

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