JuniorTheoryCommon

What does the program print (lines separated by spaces)?

PHP

<?php

$ids = ['10', 7, '1e1'];
var_dump(in_array(10, $ids));
var_dump(in_array('7', $ids, true));
var_dump(array_search(7, $ids));

bool(true) bool(false) int(1)

Expecting in_array to compare strictly: by default it uses ==, so in_array(10, ['10']) is true; pass true as the third argument to compare with ===.
Expecting array_search to return true like in_array: it returns the key of the first match, here 1, and false only when nothing matches.

Why can a missing third argument let a wrong value pass an in_array whitelist check?
What does array_search('7', $ids, true) return for this array?

JuniorTheoryCommon

PHP

<?php

$ids = ['10', 7, '1e1'];
var_dump(in_array(10, $ids));
var_dump(in_array('7', $ids, true));
var_dump(array_search(7, $ids));

bool(true) bool(false) int(1)

Expecting in_array to compare strictly: by default it uses ==, so in_array(10, ['10']) is true; pass true as the third argument to compare with ===.
Expecting array_search to return true like in_array: it returns the key of the first match, here 1, and false only when nothing matches.

Why can a missing third argument let a wrong value pass an in_array whitelist check?
What does array_search('7', $ids, true) return for this array?