PHP 7.1 New Features

nullable-functions.php

<?php
function returnStringOrNull($valueToReturn): ?string {
    return $valueToReturn;
}

echo 'LibreByte:', gettype(returnStringOrNull('LibreByte')), nl2br("\n");
echo 'null:', gettype(returnStringOrNull(null)), nl2br("\n");
echo '25:', gettype(returnStringOrNull(25)), nl2br("\n");
echo 'SdtClass object:', gettype(returnStringOrNull(new StdClass())), nl2br("\n");

nullable-param.php

<?php
function stringOrNullParam(?string $param) {
    echo 'Param: ', is_null($param) ? "'null'" : "'$param'", ", type: ", gettype($param), nl2br("\n");
}

stringOrNullParam('LibreByte');
stringOrNullParam(null);
stringOrNullParam(25);
stringOrNullParam(new StdClass());

void-functions.php

<?php
a = 10;

function voidWithoutReturn(&$param, $newValue): void {
    $param = $newValue;
}

function voidWithEmptyReturn(&$param, $newValue): void {
    $param = $newValue;
    return;
}

echo 'Initial value for a: ', $a, nl2br("\n");
voidWithoutReturn($a, 25);
echo 'Called voidWithoutReturn($a, 25), $a = ', $a, nl2br("\n");
voidWithEmptyReturn($a, 30);
echo 'Called voidWithEmptyReturn($a, 30), a = ', $a, nl2br("\n");

voidWithReturn.php

<?php
function voidWithReturn(): void {
    return 1;
}

voidWithReturnNull.php

<?php
function voidWithReturnNull(): void {
    return null;
}