CODEWITHSUNDEEP
php
panthro
panthro

Reputation: 24061

Using a var inside and outside of a function?

I set a var:

$name = "john";

Then I have a function:

function whatever(){
    $name .= " smith";
}

Outside the function I want to dump the name:

var_dump($name);

But just john is output. I've tried using:

function whatever() use ($name) {
    var_dump($name) //john
    $name .= " smith";
}

But the final var dump outside the function still does not append smith. Where am I going wrong?

Upvotes: 0

Views: 90

Answers (3)

Mohd Abdul Mujib
Mohd Abdul Mujib

Reputation: 13928

What you have encountered here is the concept of variable scope in PHP.

What ever is defined outside of a function is irrelevant inside a function, due to it having its own scope.

So you can do what you intend in multiple ways.

Method 1: Using Global Keyword

$a = 1; $b = 2;

function Sum(){
    global $a, $b;

    $b = $a + $b;
} 

Sum();
echo $b;

Note: The global keyword makes the variable available to the "global" scope, and it can be defined and accessed anywhere from any class or even from outside during the runtime, due to which, from maintenance and debugging perspective it creates a lots of hassle hence it is very much frowned upon and considered a last resort tool.

Method 2: Function Argument

$name = "john";
$lastname = "smith";
function fullname($name, $lastname){
    $name .= $lastname;
    return $name;
}
echo fullname($name, $lastname);

Method 3: Using Reference

function foo(&$var){
    $var++;
}

$a=5;
foo($a);
// $a is 6 here

Upvotes: 0

mtizziani
mtizziani

Reputation: 1016

simpliest way to do that:

$name = "john";

function merge($name) {
  return "$name smith";
}

$name = merge($name);

echo $name; // shows you: john smith

i think this is exactly what you was looking for

don't try to use outer scope vars like in javascript. thats not testable and bad practice

Upvotes: 1

L. Herrera
L. Herrera

Reputation: 490

Its a case of variable scope. What you can do here is getting it via global or passing a parameter:

// Pass by parameter
$name = "john";

function whatever($name){
    $name .= " smith";
    return $name;
}

var_dump(whatever($name));

// Calling it via global
function whatever2(){
    global $name;
    $name .= " smith";
    return $name;
}

var_dump(whatever2());

If you still want to use "use":

$name2 = "john";

$full_name = function () use ($name2){
    return $name2 . " smith";
};

var_dump($full_name());

Upvotes: 0

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