Functions in C + +

Function Prototyping 

Function prototyping is one improvement added to C++ functions. The prototype is a declaration that defines the arguments passed to the function and type of value returned by the function. It has the form : 

type function - name (argument list) ; 

Note that each argument variable must be declared independently inside the parentheses. For example: float volume (int x, float y, float z) ;  

Inline functions 

Inline functions save memory and execution time by placing the function's code directly in the program instead of jumping to it. This eliminates the overhead of passing values and control during function calls. 

Syntax:  

inline function_header 

            { 

               function_body 

           } 

Function overloading 

Overloading uses the same name for different purposes. Function overloading allows creating functions with the same name but different arguments, performing various tasks. This function polymorphism determines the correct function based on the arguments, not the function type. 

Default arguments 

C + + allows us to call a function without specifying all its arguments. In such cases, the function assigns a default value to the parameter which does not have a matching argument in the function call. Default values are specified when the function is declared. For example: float amount (float principal, int period, float rate = 0.15); 

Only trailing arguments can have default values i.e. we must add defaults from right to left. We cannot provide a default value to an argument in the middle of list.