在PHP函数中访问全局变量

Question

I'm new to php and I can't understand why is it that the variable "cons" isn't recognized by the the compiler when used inside the function "func", in the following code:

$cons = 1;

function plusCons($num) {
   return $num + $cons;
}

is it impossible to use global variables inside of a function's scope?

Answer 1

In order to access global variables within a PHP function, you need to use the global keyword to import the variable:

$cons = 1;

function plusCons($num) {
   global $cons;

   return $num + $cons;
}

Answer 2

This also will work for you:

$cons = 1;

function plusCons($num ,$cons) {
  return $num + $cons;
}

echo plusCons(2 , $cons); // this will output 3