Why Doesn't My Pointer Change After Passing It to a Function?

Understanding the Issue: Unmodified Pointer Passing

In this code snippet, the clickOnBubble function receives a pointer to a Bubble object (targetBubble) and a vector of Bubble pointers (bubbles). The issue is that after the function is executed, the targetBubble pointer passed to the function remains unmodified. The expectation is that the function should change the targetBubble pointer to point to a specific Bubble in the bubbles vector, but this is not happening.

Passing a Copy of the Pointer

The reason for this behavior is that you are passing a copy of the targetBubble pointer, not a reference. When you pass a copy of a pointer, any changes made to the pointer within the function will not be reflected in the original pointer outside the function.

Solution: Using a Pointer Reference or Pointer to Pointer

To ensure that the targetBubble pointer outside the function is changed, you need to pass a reference to the pointer or use a pointer to pointer.

Using a Pointer Reference:

void clickOnBubble(sf::Vector2i &mousePos, std::vector<Bubble *>& bubbles, Bubble *&targetBubble) {
    targetBubble = bubbles[i]; // Modified pointer here is reflected outside function
}

Using a Pointer to Pointer:

void clickOnBubble(sf::Vector2i &mousePos, std::vector<Bubble *>& bubbles, Bubble **targetBubble) {
    *targetBubble = bubbles[i]; // Modified pointer here is reflected outside function
}

In both cases, the modified targetBubble pointer within the function will be reflected in the original targetBubble pointer outside the function.

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