PHP Array Reference problem

I want to know how she does this quote.

This is a quote.
And when I cut out the quotes, I want to know how she quoted the array one over the other.

Reply content:

I want to know how she does this quote.

This is a quote.
And when I cut out the quotes, I want to know how she quoted the array one over the other.

Just draw a picture. The array of PHP is a graph structure
Traversal array if the current node has a parent node, place the current node below the parent node
If there is no parent node (that is, the root node), join the current node $tree []

When you use a reference, the original value changes when you manipulate the reference, and when you pass the value, another array is generated when you manipulate it.
That's what I'm telling you, "a." And "a" such a thing when you manipulate A's avatar is equivalent to a value.

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