<?php function myAge($birthYear) { // defines a function, this one is named "myAge" $yearsOld = date('Y') - $birthYear; // calculates the age return $yearsOld . ' year' . ($yearsOld != 1 ? 's' : ''); // returns the age in a descriptive form } echo 'I am currently ' . myAge(1981) . ' old.'; // outputs the text concatenated // with the return value of myAge() // As the result of this syntax, myAge() is called. ?>
/* multi line or inline comment */ echo "Hello world\n"; // variable names are case sensitive // function and class names are not !!!!! echo NULL == NULL; echo NULL == false; // they are !!! echo "\n"; // $birthYear, yearsOld are case sensitive function myAge($birthYear) { // function 'date' or 'DATE' case insensitive $yearsOld = dAtE('Y') - $birthYear; return $yearsOld . ' year' . ($yearsOld != 1 ? 's' : ''); } echo 'I am currently ' . myAge(1981) . " old.\n"; echo 'I am currently ' . MYAGE(1981) . " old.\n"; echo function_exists('myAge') . "\n"; // can be handy // lambda expression / closures function getAdder($x) { return function ($y) use($x) { return $x + $y; }; } $adder = getAdder(8); echo $adder(2) . "\n"; class Person { public static $count = 0;