
Type: LanguageSpecification

Status: Active

Resolution: Unresolved

Labels:None

Impact:Unknown 'null' severity

Likelihood:Unknown 'null' severity
Using the same value on either side of a binary operator is almost always a mistake. In the case of logical operators, it is either a copy/paste error and therefore a bug, or it is simply wasted code, and should be simplified. In the case of bitwise operators and most binary mathematical operators, having the same value on both sides of an operator yields predictable results, and should be simplified.
This rule ignores *, +.
Noncompliant Code Example
if a == a { // always true doZ() } if a != a { // always false doY() } if a == b && a == b { // if the first one is true, the second one is too doX() } if a == b  a == b { // if the first one is true, the second one is too doW() } var j = 5 / 5 //always 1 var k = 5  5 //always 0
Exceptions
Leftshifting 1 onto 1 is common in the construction of bit masks, and is ignored.
var i = 1 << 1; // Compliant var j = a << a; // Noncompliant