Pass by Value

• can not change the value of the actual parameter

Pass by Reference

• can change value of parameter

C++ Arrays

• passed by reference

C++ non-arrays

• normally passed by value

Example C++ how to pass by reference

• void function (CarType& car, float x)
• x is by value, car is by reference
• can do in function car.price = X*33.3;
• invocation of fuction      function(myCar, 0.03);

void  AdjustForInflation(CarType&  car,  float  perCent)

// Increases price by the amount specified in perCent	
{

    car.price = car.price * perCent + car.price;  
   
} ;



SAMPLE CALL

AdjustForInflation(myCar, 0.03);

Example C++ how to pass by value

bool LateModel(CarType car, int date)
// Returns true if the car’s model year is later than or
// equal to date; returns false otherwise.

{ return ( car.year >= date ) ; } ;

• invocation of function SAMPLE CALL
  
  if ( LateModel(myCar, 1995) )
          std::cout << myCar.price << std::endl ;