What is the best way to determine if a variable is exiting or not?
isset($x) can be used. But if it’s defined like this
$x=NULL
The answer will be false even if the variable is completely valid.
What is the best way to determine if a variable is exiting or not?
isset($x) can be used. But if it’s defined like this
$x=NULL
The answer will be false even if the variable is completely valid.
Can expressions be passed as by-reference arguments or only variables can?
Only variables can be passed as by-reference.