No Double Operators

ID

php.no_double_operators

Severity

low

Remediation Complexity

trivial

Remediation Risk

low

Remediation Effort

low

Resource

Reliability

Language

Php

Tags

reliability, suspicious-operator

Description

Reports two operator shapes that are almost always typing mistakes: a doubled unary operator (!!$x or ~~$x), and a plain assignment whose value begins with an immediately adjacent unary + or - ($a =+ $b, $a =- $b), which is the classic mistype of the augmented operators += and -=.

Rationale

!!$x applies logical negation twice, returning the original boolean value, and ~~$x applies bitwise complement twice, returning the original integer — both are no-ops that read as if they do something. Worse, $a =+ $b looks like the augmented add $a += $b but actually parses as $a = (+$b), silently overwriting $a instead of incrementing it. These patterns are surface typos with no legitimate use.

<?php
$flag = !!$value;   // FLAW — double negation, equivalent to (bool) $value written by mistake
$mask = ~~$bits;    // FLAW — double complement, a no-op
$total =+ $amount;  // FLAW — meant += but overwrites $total with +$amount
$total += $amount;  // OK — augmented addition
$delta = -$amount;  // OK — assignment of a negated value (note the space)
$flag = !$value;    // OK — single negation

Remediation

For a doubled !, use an explicit (bool) cast if a boolean is intended, or remove the redundant operator. For =+ / =-, decide whether an augmented operation (+= / -=) or a spaced assignment of a signed value (= -$x) was meant, and write it explicitly.

References