Which line is the heading definition for the function main?
A function is a group of statements that together perform a task. Every C program has at least one function, which is main(), and all the most trivial programs can define additional functions. Show You can divide up your code into separate functions. How you divide up your code among different functions is up to you, but logically the division is such that each function performs a specific task. A function declaration tells the compiler about a function's name, return type, and parameters. A function definition provides the actual body of the function. The C standard library provides numerous built-in functions that your program can call. For example, strcat() to concatenate two strings, memcpy() to copy one memory location to another location, and many more functions. A function can also be referred as a method or a sub-routine or a procedure, etc. Defining a FunctionThe general form of a function definition in C programming language is as follows − return_type function_name( parameter list ) { body of the function } A function definition in C programming consists of a function header and a function body. Here are all the parts of a function −
ExampleGiven below is the source code for a function called max(). This function takes two parameters num1 and num2 and returns the maximum value between the two − /* function returning the max between two numbers */ int max(int num1, int num2) { /* local variable declaration */ int result; if (num1 > num2) result = num1; else result = num2; return result; } Function DeclarationsA function declaration tells the compiler about a function name and how to call the function. The actual body of the function can be defined separately. A function declaration has the following parts − return_type function_name( parameter list ); For the above defined function max(), the function declaration is as follows − int max(int num1, int num2); Parameter names are not important in function declaration only their type is required, so the following is also a valid declaration − int max(int, int); Function declaration is required when you define a function in one source file and you call that function in another file. In such case, you should declare the function at the top of the file calling the function. Calling a FunctionWhile creating a C function, you give a definition of what the function has to do. To use a function, you will have to call that function to perform the defined task. When a program calls a function, the program control is transferred to the called function. A called function performs a defined task and when its return statement is executed or when its function-ending closing brace is reached, it returns the program control back to the main program. To call a function, you simply need to pass the required parameters along with the function name, and if the function returns a value, then you can store the returned value. For example − #include We have kept max() along with main() and compiled the source code. While running the final executable, it would produce the following result − Max value is : 200 Function ArgumentsIf a function is to use arguments, it must declare variables that accept the values of the arguments. These variables are called the formal parameters of the function. Formal parameters behave like other local variables inside the function and are created upon entry into the function and destroyed upon exit. While calling a function, there are two ways in which arguments can be passed to a function −
By default, C uses call by value to pass arguments. In general, it means the code within a function cannot alter the arguments used to call the function. In which line is the function header?Answer: The first line of the function definition which starts with the 'def' keyword is the function header. Syntax: def function_name(parameters):
What is the function of Main?Every C program has a primary function that must be named main . The main function serves as the starting point for program execution. It usually controls program execution by directing the calls to other functions in the program.
What is main function header?Function definition
The header includes the name of the function and tells us (and the compiler) what type of data it expects to receive (the parameters) and the type of data it will return (return value type) to the calling function or program. The body of the function contains the instructions to be executed.
What is the first line of a function definition called?The first line of the function definition is called the header; the rest is called the body. The header has to end with a colon and the body has to be indented. By convention, the indentation is always four spaces (see Section 3.13). The body can contain any number of statements.
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