Php operator null coalescing

- Php elvis operator vs null coalescing
- Php null coalescing operator version
- Php null coalescing operator chaining
- Php null coalescing operator assignment
- Php null coalescing operator object
- Php null coalescing operator array key
- Php null coalescing operator empty
- Php 8 null coalescing operator
- Php shorthand null coalescing operator
- Php chain null coalescing operator
- Php double null coalescing operator
- Php isset vs null coalescing operator
- Null coalescing operator php empty array
- Php null coalescing operator array
- Php null coalescing operator comparison