Parameter passing convention in a programming language, is the method used to pass one or more values (called actual parameters) to a function by means of a function call, such as the following: square (2); This function call launches a function that squares the supplied parameter (2), returning 4. One fundamental difference among programming languages concerns what is done with the returned value. In a call-by-value convention, the function places the returned value in a new memory location and leaves the original actual parameter intact. In a call-by-reference convention, the function replaces the actual parameter (2) with the returned value (4) at the function call’s location. See function, a function call, parameter.
Technipages Explains Parameter Passing Convention
Passing parameter convention is a technique in programming, in which an actual parameter is passed to a function; this happens when a function calls another function. A parameter is an intrinsic property of the procedure which is included in its definition, and there are formal parameters and actual parameters.
Formal parameters are usually written in the function prototype, and function header of the definition, i.e. they appear in function declarations. An actual parameter is the values passed in the call of a function, i.e. they appear in the function call.
So when a function is called, the actual parameters are passed, which are also known as arguments. Service is called by invocation, which is either by value or reference. In the call by value, the function creates its copy of the argument (actual parameter) and then uses it, it replicates the value of the actual parameter. The call by reference, the function when called, refers to another value (original) which is under a different name. The formal parameter becomes a reference to the actual parameter in calling a function.
It is practiced in the C and C++ programming languages, and Java only supports a call by value. All C functions are written using functions to make them re-usable and understandable.
Common Uses of Parameter Passing Convention
- Parameter passing convention is only applicable to C programs languages, and java only supports a function called by value.
- Parameter passing convention is used for passing objects on Foundation Classes method calls is if the object is mandatory, pass by reference; if it is optional pass by the pointer.’
- Parameter passing convention is used in C programs, and functions calling make c programs re-usable and understandable
Common Misuses of Parameter Passing Convention
- When parameter passing convention is exhibited, actual parameters are not sent, so a function does not call another.
- When a parameter passing convention calls a parameter by reference, the parameter creates a copy of itself and then uses it