by Dinesh Thakur Category: Functions

Any value assigned to an automatic variable within a function is lost once the control returns from the called function to the calling function. However, there may be a situation where the value of the local variable needs to be preserved even after the execution of the function gets over. This need can be fulfilled by declaring the variable as static. A static variable is commonly used when it is necessary for a function to remember a value between its calls. To understand the concept of static variables, consider this example.

 
by Dinesh Thakur Category: Functions

Like C, C++ enables to pass arguments to the main () function also. These arguments are passed by typing them after the program name on the command line. Hence, these arguments are known as command line arguments. Command line arguments help in providing data to the program.

 
by Dinesh Thakur Category: Functions

In addition to call by value, a function can also be called by reference. C++ provides two ways of passing arguments as reference to a function. The arguments can be passed either as a reference type or as a pointer type.

 
by Dinesh Thakur Category: Functions

When a function is called by value, the values of the actual arguments are copied into the formal arguments and the function works with these copied values. As a result, any changes made to the copied value in the called function do not affect the value of the actual argument in the calling function.

 
by Dinesh Thakur Category: Functions

In order to use a function in different parts of a program, the function must be called or invoked by another function. In C++, functions are called by specifying the name of the function, followed by the parentheses. The parentheses mayor may not contain a list of arguments depending on the function definition.

 
by Dinesh Thakur Category: Functions

In order to use a function in a program, the function must be first defined somewhere in a program. A function definition contains the code that specifies the actions to be performed. The syntax for defining a function is

 
by Dinesh Thakur Category: Functions

Like variables, functions also need to be declared before they are used in programs. A function declaration is also known as function prototype. Function prototype is a model or a blueprint for a function that informs the C++ compiler about the return type, the function name, and the number and data type of the arguments passed to the function. Function name together with parameter list is known as function signature and it does not include return type of a function. The syntax for declaring a function is



 

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About Dinesh Thakur

Dinesh ThakurDinesh Thakur holds an B.SC (Computer Science), MCSE, MCDBA, CCNA, CCNP, A+, SCJP certifications. Dinesh authors the hugely popular blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps. For any type of query or something that you think is missing, please feel free to Contact us.



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