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copied!<p>Firstly, PHP doesn't support nested functions in the way you are trying to use them. </p> <p>You can write this:</p> <pre><code>function outer() { function inner() {} } outer(); </code></pre> <p>But all that happens is that when <code>outer();</code> is executed, the <code>inner()</code> function is declared as a normal function. So the code is exactly the same as this:</p> <pre><code>function outer() {} function inner() {} outer(); </code></pre> <p>Secondly, variables in PHP (unless prefixed, with a class or object name) are always scoped to the current function. The <code>global</code> keyword <em>imports a reference</em> to a global variable into the current function's scope; it cannot be used to <em>export</em> a variable which was already defined. </p> <p>It is generally best to only use the <code>global</code> keyword at the very beginning of a function, to import all the global variables needed by that function. Even better, do not use global variables, since they lead to "spaghetti code" which is hard to understand and debug.</p> <p>If you declare the variable <code>global</code> <em>before</em> running <code>extract</code>, this will work, but <strong>I would strongly advise against using either feature</strong>.</p> <pre><code>function foo_with_too_much_magic() { // Import global variable. Very hard to track where this came from. global $some_var; // Let's assume this array comes from somewhere and isn't hard-coded $some_array = array('some_var' => 'some_value'); // Export variables from an array. This is like telling PHP to write different code each time it runs, with different variable names. extract( $some_array ); } foo_with_too_much_magic(); var_dump($some_var); </code></pre> <p>Here is a version of the above without the discouraged features:</p> <pre><code>function foo_with_no_magic() { // Let's assume this array comes from somewhere and isn't hard-coded $some_array = array('some_var' => 'some_value'); // You know which variable you want, so don't need the magic "export" // Note that you don't have to call it $some_var $some_var = $some_array['some_var']; // Now you have the variable, you can manipulate it, pass it to another function, or return it // In fact, you could also return $some_array['some_var'] directly, without the extra assignment return $some_var; } // This variable name no longer needs to be the same as what was used in the foo_with_no_magic() function $some_var = foo_with_no_magic(); var_dump($some_var); </code></pre>

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