PHP: how to get variable from function in another function? -

this question has answer here:

• accessing variable defined in parent function 5 answers

example

function a(){     $num = 1;      function b(){         echo $num; // how $num value?     } } 

in case global not working, because $num isn't global variable.

function a() {     $num = 1;     function b($num) {         echo $num;     };     b($num); } a();