Checking for relative vs absolute paths/URLs in PHP

Question

I need to implement functions to check whether paths and urls are relative, absolute, or invalid (invalid syntactically- not whether resource exists). What are the range of

Answer 1

I think best is

$test = [
'/link?param=1'=>parse_url('/assa?ass'),
'//aaa.com/link?param=1'=>parse_url('//assa?ass'),
'http://aaa.com/link?param=1'=>parse_url('http://as.plassa?ass')
];