Larger Than Int

<?php

printf('%u', -1);
print PHP_EOL;
print PHP_INT_MAX;

printf() displays an integer as a string. The %u format treats the integer as an unsigned integer, while PHP only process signed integer. Here, -1 is actually 0xffffffffffffff, and the resulting string is actually twice as large as the largest PHP integer PHP_INT_MAX.

Since it is returned as a string, it looks like it is larger, but PHP converts its to float as soon as it needs to process it.

See Also

• Original Toot

• Larger then PHP_INT_MAX [Try me]

PHP Features

• php_int_max

• printf

• signed-integer

Last updated: 14 July 2026