In PHP, references allow you to create multiple names for the same variable, enabling you to access and manipulate its value through different
identifiers. They are denoted by the ampersand symbol & placed before the variable name during declaration or assignment.
When a reference is used in a foreach loop instead of using a simple variable, the reference remains assigned and keeps its "value"
which is a reference, even after the foreach execution.
What is the potential impact?
Not unsetting the reference can lead to bugs later in the code, as most of the time, this behavior is different from what the developer is
expecting. For example, the reference may be used incorrectly with the previous value.
To avoid unexpected side effects, it is recommended to always unset a reference that is used in a foreach loop.
