Why doesn't a function in php have access to external variables?

Question

PHP

let a = 5;

function inc() {
    return a;
}
console.log(inc()); // 5

$a = 5;
function inc() {
  return $a;
}

if(true) {
  echo $a; // 5
}

echo inc();  // undefined

Why doesn't a function in php have access to external variables?

Answer 1

According to the prophecy.
If you want the php function to see an external variable, then you need to import it into the function using
global $a;

Answer 2

Variable scope for full immersion
https://www.php.net/manual/en/language.variables.s...

$a = 5;
function inc() {
  return $GLOBALS["a"];
}

var_dump($a); //int(5)

var_dump(inc()); //int(5)

Answer 3

If you just need to put devices on the map, then The Dude from Mikrotik is perfect.

Answer 4

Thanks, I'll try!