C++ function parameters



In C++, function parameters are variables that are defined within the parentheses of a function declaration or definition.

 These variables are used to pass values or references to the function.


Function parameters are declared with a type followed by a name, and multiple parameters can be separated by commas. For example, the following function declaration has two parameters of type int:


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void myFunction(int x, int y); 


When a function is called, the values or references passed as arguments are assigned to the corresponding parameters in the function definition. 

For example, in the following function call:


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myFunction(5, 10); 


the value 5 is assigned to the parameter x, and the value 10 is assigned to the parameter y.


Function parameters can be passed by value, reference, or pointer. When passed by value, a copy of the argument value is made and passed to the function. 

When passed by reference or pointer, the function receives the memory address of the argument, allowing it to directly modify the original value. 

The choice of passing method depends on the needs of the function and the efficiency of passing large objects by reference or pointer.


Function parameters can also have default values, which are used if no argument is provided for that parameter when the function is called.

 This allows for more flexible function usage without requiring the caller to specify every parameter value. For example:


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void myFunction(int x, int y = 0); 


In this function, if no argument is provided for y when the function is called, it will default to 0.