PHP 7.4 End of Life

String to number comparisons

In PHP 8, 0 == "foo" is false; in PHP 7 it was true. Comparisons between numbers and non-numeric strings now compare as strings. This silently changes the result of loose comparisons, switch and in_array() without strict mode.

<?php
var_dump(0 == 'foo');
var_dump(in_array('abc', [0]));
switch (0) {
    case 'a': echo 'matched a'; break;
    default: echo 'default';
}

Run on PHP 7.4 →Run on PHP 8.0 →

Removed functions: each(), create_function() and more

each(), create_function(), money_format() and others were removed, and calling them is now a fatal error. Replace each() loops with foreach and create_function() with closures.

<?php
$arr = ['a' => 1, 'b' => 2];
while (list($k, $v) = each($arr)) {
    echo "$k=$v ";
}

Run on PHP 7.4 →Run on PHP 8.0 →

Curly brace string offsets

$str{0} was deprecated in 7.4 and is a parse error in PHP 8. Use $str[0].

<?php
$s = 'PHP';
echo $s{0};

Run on PHP 7.4 →Run on PHP 8.0 →

Warnings became errors

Many internal functions now throw TypeError or ValueError where they used to return null with a warning, for example strlen([]) or array_combine() with arrays of different lengths. Arithmetic on arrays and non-numeric strings throws as well.

<?php
try {
    echo strlen([]);
} catch (TypeError $e) {
    echo get_class($e), ': ', $e->getMessage();
}

Run on PHP 7.4 →Run on PHP 8.0 →

Unparenthesized nested ternaries

$a ? $b : $c ? $d : $e is a fatal error in PHP 8. Add parentheses to say what you mean.

Resources became objects

GD images, cURL handles and others are now objects (GdImage, CurlHandle). Code that checks is_resource($img) must check for the object or for false instead.