PHP variables in anonymous functions

php function variables global-variables anonymous
einord picture einord · Jul 10, 2012 · Viewed 42.3k times · Source

I was playing around with anonymous functions in PHP and realized that they don't seem to reach variables outside of them. Is there any way to get around this problem?

Example:

$variable = "nothing";

functionName($someArgument, function() {
  $variable = "something";
});

echo $variable;  //output: "nothing"

This will output "nothing". Is there any way that the anonymous function can access the $variable?

Answer

nickb picture nickb · Jul 10, 2012

Yes, use a closure:

functionName($someArgument, function() use(&$variable) {
  $variable = "something";
});

Note that in order for you to be able to modify $variable and retrieve the modified value outside of the scope of the anonymous function, it must be referenced in the closure using &.

Related questions

Changing a global variable from inside a function PHP

I am trying to change a variable that is outside of a function, from within a function. Because if the date that the function is checking is over a certain amount I need it to change the year for the …

Read More
PHP global or $GLOBALS

Is there a best practice / recommendation when I want to use a variable declared outside of a function when it comes to using: global $myVar $GLOBALS['myVar'] Thank you.

Read More
what does a php function return by default?

If I return nothing explicitly, what does a php function exactly return? function foo() {} What type is it? What value is it? How do I test for it exactly with === ? Did this change from php4 to php5? Is there a …

Read More