Functions and Pointers

Functions and Pointers :

Pointers could be passed to functions as parameters just like we pass ordinary variables as parameters to the functions: Let’s understand how to pass pointers to a function by an example code: main {  int x = 70 ; cout<< x;  IncreaseByTen( &x ); // calling the function IncreaseByTen passing     // address of x   cout<<  x;  }

//function IncreaseByTen void IncreaseByTen(int *ptr ) {   *ptr += 10; }

Predict the output of the above code. The output of the above code snippet would be 70 and 80. This is because we have called the function IncreaseByTen by passing the address of the variable x as an actual parameter. This address is being copied into the formal parameter ptr of the function, which is a pointer variable. Since this variable holds the address of the x so any changes made at this address ( by statement : *ptr+=10 ) would made changes on the value stored at that address i.e. on the value of x. Similarly we can have more than one pointer variables as formal parameters to a function separated by comma.