Defining functions (= methods) in C

  • Syntax to define a function in C: 

       return-Type   functionName ( formal-parameters )
   {// function-body 
       local variables definitions

       statements
   }

    Example: function that returns the square of a number 

       float square( float x )                  
   {
      float r;         // Define a local variable         

      r = x * x;       // Statement
      return ( r );    // Return statement
   }

Calling a functin in C   (uses the same syntax as Java)

  • Syntax to call (= invoke) a function: 

      // Invoking a void type function:
     
  functionName ( arguments )  


    
  // Invoking a non-void type function:

  var = functionName ( arguments )

  • Example: 

       float a = 4.0, b;

   b = square( a );   // Same syntax as in Java !

Remember:   C is not object oriented

  • C is not an object oriented programming language

    Meaning:

      • C does not have instance methods

        (instance methods works with objects and always use a implicit parameter (this))

  • C's functions are similar to static methods in Java:

      • C functions do not have implicit parameters

        I.e.: all parameters of a C function are listed in the parameter list of the function