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



 
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

Arguments in a function can also be of array type. When the arrays are passed by value in a function, it is written as shown in the following example:

 
by Dinesh Thakur Category: Functions

Auto

 

The values of the variables are not retained beyond the scope of a function in which they are declared. The values of the variables can be accessed only during the execution of a function. Whatever variables are declared in a function, they are assumed implicitly of auto storage type. For example in the following program segment

 
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.

 
 

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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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