Call function within a function PHP

1    function foo($i){
2       return bar($i)*4;
3       function bar($i){
4           return $i*4;
5           }
6       }
7    echo foo(4);

return

Fatal error: Call to undefined function bar() in /var/www/index.php on line 2

why doesn't it work? it works well in javascript, while it works when i do this:

function foo($i){
   return bar($i)*4;
  开发者_运维问答 }

function bar($i){
   return $i*4;
   }

Define the function above your return value, otherwise it never gets executed.

<?php
function foo($i){
    function bar($i){
        return $i*4;
    }
    return bar($i)*4;
}
echo foo(4);
?>

It doesn't work as you are calling bar() before it has been created. See example 2 here:- http://www.php.net/manual/en/functions.user-defined.php

Your code never reach function bar(...), therefore it's never defined.

You need to put your bar() function before your foo() or before the return bar. (Answer based on your first example).

With your second example you probably define bar() before you use foo() therefore bar() is defined and it works fine.

So as long as you have your function defined when you hit a certain spot in your code it works fine, no matter if it's called from within another function.

If you define function within another function, it can be accessed directly, but after calling parent function. For example:

function a () {
    function b() {
    echo "I am b.";
   }
echo "I am a.<br/>";
}
//b(); Fatal error: Call to undefined function b() in E:\..\func.php on line 8
a(); // Print I am a.
b(); // Print I am b.

Execution not execute after return statement

change your code like this

 function foo($i){
 function bar($i){
  return $i*4;
 }
 return bar($i)*4;     
}
echo foo(4);

For the sake of having a "recent" answer, here's what I did:

function printRx($conn, $patient)
{
    function rows($rows, $tod)
    {
        for ($x = 0; $x < count($tod); $x++) {
            if ($tod[$x] == 1) {
                $rows++;
                break;
            }
        }
        return $rows;
    }
    $tod['prn'] = (explode('|', $row['prn'])) ?? null;
    $rows = rows($rows, $tod['prn']);
    return;
}

Works beautifully