1.2.1349. Use Same Types For Comparisons

Beware when using inequality operators that the type of the values are the same on both sites of the operators.

Different types may lead to PHP type juggling, where the values are first cast to one of the used types. Other comparisons are always failing, leading to unexpected behavior.

This applies to all inequality operators, as well as the spaceship operator.

This analysis skips comparisons between integers, floats and strings, as those are usually expected.

Thanks to Jordi Boggiano and Filippo Tessarotto.

<?php

// Both are wrong, while one should be true (depending on when you read this)
var_dump('1995-06-08' < new DateTimeImmutable());
var_dump('1995-06-08' > new DateTimeImmutable());

enum x : int {
    case A = 1;
    case B = 2;
}

// Both are false as objects are compared, not their integer value
var_dump(x::A < x::B);
var_dump(x::A > x::B);

var_dump(x::A->value < x::b->value);
var_dump(x::A->value > x::b->value);

?>

1.2.1349.1. Connex PHP features

• inequality

• enum-case

• type-juggling

1.2.1349.1.1. Suggestions

• Make sure that the same time

1.2.1349.1.2. Specs

Short name	Structures/UseSameTypesForComparisons
Rulesets	All, Analyze
Exakat since	2.4.2
PHP Version	All
Severity	Minor
Time To Fix	Quick (30 mins)
Precision	Very high
Available in	Entreprise Edition, Exakat Cloud