Does toCharArray() consumes space in Big O

In calculating the space complexity of algorithms, we're told the easiest way to find out about additional space is the creation of a data structure like Set, Map, Stack etc.

Take the below code as example that reveres a string (In Java)

private String reverse(String string){

    if (string == null || string.length() == 0) return string;

    char[] strArray = string.toCharArray(); // Does this consume space?

    int first = 0, last = strArray.length - 1;

    while (first < last){
        char temp = strArray[first];
        strArray[first++] = strArray[last];
        strArray[last--] = temp;
    }


    return String.valueOf(strArray);
}

Does converting the str to a character array consume space