JuniorTheoryCommon

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

PHP

<?php

var_dump((bool) '0');
var_dump((bool) '0.0');
var_dump((bool) []);
var_dump((bool) ' ');

bool(false) bool(true) bool(false) bool(true)

Expecting '0.0' to be false like '0': the cast to bool looks at the text, and only '' and '0' are false strings, so '0.0' is true.
Expecting [] to be true, as in JavaScript: in PHP an empty array is false, and only an array with at least one element is true.

JuniorTheoryCommon

PHP

<?php

var_dump((bool) '0');
var_dump((bool) '0.0');
var_dump((bool) []);
var_dump((bool) ' ');

bool(false) bool(true) bool(false) bool(true)

Expecting '0.0' to be false like '0': the cast to bool looks at the text, and only '' and '0' are false strings, so '0.0' is true.
Expecting [] to be true, as in JavaScript: in PHP an empty array is false, and only an array with at least one element is true.