functions theory

Functions can be called in 2 ways either with arguments or without arguments in C program. So, these functions may or may not return values to the calling function. So, the functions are divided into 4 categories listed below : -

1. C function with arguments (parameters) and with return value
2. C function with arguments (parameters) and without return value
3. C function without arguments (parameters) and without return value
4. C function without arguments (parameters) and with return value

S.no	C function	syntax
1	with arguments and with return values	int function ( int );         // function declaration function ( a );                // function call int function( int a )       // function definition {statements;  return a;}
2	with arguments and without return values	void function ( int );     // function declaration function( a );                // function call void function( int a )   // function definition {statements;}
3	without arguments and without return values	void function();             // function declaration function();                     // function call void function()              // function definition {statements;}
4	without arguments and with return values	int function ( );             // function declaration function ( );                  // function call int function( )               // function definition {statements;  return a;}

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