This means this only works with fixed arrays of one particular length. sin() and cos() take radians, not degrees, so we need to convertĬonstexpr double pi // we can now do this since the array won't decay Void getSinCos(double degrees, double& sinOut, double& cosOut) #include // for std::sin() and std::cos() One way to return multiple values is using reference parameters: #include
However, functions can only have one return value. Sometimes we need a function to return multiple values. Returning multiple values via out parameters This snippet produces the output:Īs you can see, the function changed the value of the argument from 5 to 7! When we call addTwo(value), ref becomes a reference to main’s value variable. This program is the same as the one we used for the pass by value example, except addTwo’s parameter is now a reference instead of a normal variable. The following example shows this in action: void addTwo(int& ref) Since a reference to a variable is treated exactly the same as the variable itself, any changes made to the reference are passed through to the argument! When the function is called, ref will become a reference to the argument. To pass a variable by reference, we simply declare the function parameters as references rather than as normal variables: void addTwo(int& ref) // ref is a reference variable
Pass by reference solves both of these issues. While this is often suitable, there are cases where it would be more clear and efficient to have the function modify the argument passed in. Second, when passing arguments by value, the only way to return a value back to the caller is via the function’s return value. In many cases, this is a needless performance hit, as the original argument would have sufficed. First, when passing a large struct or class to a function, pass by value will make a copy of the argument into the function parameter. While pass by value is suitable in many cases, it has a couple of limitations.
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