<?php
if(defined('B')) {
function b() {
echo "hello from `".__FUNCTION__."`\n";
}
}
echo function_exists("b") ? "b is defined\n" : "b is not defined\n";
a();
echo function_exists("b") ? "b is defined\n" : "b is not defined\n";
b();
a();
echo function_exists("b") ? "b is defined\n" : "b is not defined\n";
b is not defined
Fatal error: Uncaught Error: Call to undefined function a() in /in/LRVrR:10
Stack trace:
#0 {main}
thrown in /in/LRVrR on line 10
Process exited with code 255.