In programming, there are two common ways of passing arguments to a function: call by value and call by reference.
In call by value, a copy of the variable is passed to the function. This means that the value of the original variable remains unchanged, even if it is modified within the function. In this process, the actual and formal arguments are created in different memory locations, ensuring that changes to the formal argument do not affect the original value of the actual argument.
On the other hand, in call by reference, the variable itself is passed to the function. This means that any changes made to the formal argument within the function will also change the value of the actual argument. In this case, the actual and formal arguments are created in the same memory location, ensuring that changes to the formal argument directly affect the original value of the actual argument.
It is important to note that not all programming languages support call by reference. Some languages, like Java, only support call by value, while others, like C++, support both. The choice of which method to use depends on the requirements of the program and the language being used.
In summary, call by value and call by reference are two ways of passing arguments to a function. Call by value involves passing a copy of the variable, while call by reference involves passing the variable itself. This results in different memory locations for actual and formal arguments in call by value, and the same memory location in call by reference.