How Can I Modify a Pointer Variable from Within a Function in C ?

Function Modifying Pointer Variable

The code provided involves a function clickOnBubble that attempts to modify a pointer variable targetBubble. However, the changes made within the function do not reflect in the caller's scope. This is because the function is passing a copy of the pointer, not a reference to it.

To modify a pointer variable from within a function, one needs to utilize a reference to pointer or a pointer to pointer.

Option 1: Reference to Pointer

In this approach, a reference to the pointer is passed as an argument to the function:

void clickOnBubble(sf::Vector2i &mousePos, std::vector<Bubble *>& bubbles, Bubble *&targetBubble) {
    targetBubble = bubbles[i];
}

This reference allows the function to modify the value of the targetBubble pointer directly, affecting the original variable in the caller's scope.

Option 2: Pointer to Pointer

Alternatively, a pointer to pointer can be used:

void clickOnBubble(sf::Vector2i &mousePos, std::vector<Bubble *>& bubbles, Bubble **targetBubble) {
    *targetBubble = bubbles[i];
}

In this case, the function receives a pointer to the targetBubble pointer. Modifying the value pointed to by the pointer (i.e., *targetBubble) indirectly changes the original targetBubble pointer in the caller's scope.

The above is the detailed content of How Can I Modify a Pointer Variable from Within a Function in C ?. For more information, please follow other related articles on the PHP Chinese website!