What does an Array + int do as one parameter?

Question

I'm looking at some source code and within the code it has some code I don't fully understand. Below is a basic pseudo example that mimics the part I'm having trouble understanding:

    float *myArray;

    object(){
        myArray = new float[20];
    }

    ~object(){   
    }

    void reset(){
        delete [] myArray;
    }

    void myMethod(float *array){
        for (int i = 0; i < 20; i++){
            array[i] = 0.5f;
        }
    }

Now in another method body there's:

    void mySecondMethod(){
        myMethod(myArray + 10);
    }

It's the second method I don't get: What does it mean when you pass an array pointer and an int into a parameter that wants an array pointer? I'm just trying to bolster my knowledge, I've been trying to search about it but have found no information.

Answer 1

It simply means "the address of the 11th element in this array".

This is an example of pointer arithmetic, a core feature of C (and also of C++ although it's perhaps considered a bit "low-level" there).

The expression means "take the address of the first element of myArray, and add the size of 10 elements to that".

It works the same as myArray[10], since the indexing operator is really sugar for *(myArray + 10).

Answer 2

myArray[10]  == *(myArray + 10)

&myArray[10] == myArray + 10