wp-includes/load.php:1439Converts a value to non-negative integer.
$maybeintmixedintfunction absint( $maybeint ) { return abs( (int) $maybeint );}Introduced in 2.5.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/load.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.