<?php function increment($val) { return ++$val; } $val = 1; echo increment($val) . PHP_EOL; echo "Function 2:" . PHP_EOL; function increment2($val) { return $val++; } $val = 1; echo increment2($val) . PHP_EOL;
$var = "contents 1"; fn(); echo "outside the function, \$var = " . $var . "<br/>"; function fn2() { global $var; $var = "contents"; echo "inside the function, \$var = " . $var . "<br/>"; } fn2(); echo "outside the function, \$var = " . $var . "<br/>"; /*未改变原变量的引用*/ function increment1($value, $amount = 1) { $value = $value + $amount; } echo "without '&': <br/>"; $a1 = 10; echo $a1 . "<br/>"; increment1($a1); echo $a1 . "<br/>"; /*引用传递参数*/ function increment2(&$value, $amount = 1) { $value = $value + $amount; } echo "with '&': <br/>"; $a2 = 10; echo $a2 . "<br/>"; increment2($a2); echo $a2 . "<br/>";