Avoid binary operators with identical members

Why you should care

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.

How we detect

CAST Highlight counts one occurrence each time same values are detected before and after a logical operator as: ‘&&’ or ‘||’

Exceptions: This code insight ignores *, +, << and =.

Bad Code

func main() {
  v1 := (true && false) && (true && false) // Noncompliant

Good Code

func main() {
  v1 := (true && false) // Compliant



About CAST and Highlight’s Code Insights

Over the last 25 years, CAST has leveraged unique knowledge on software quality measurement by analyzing thousands of applications and billions of lines of code. Based on this experience and community standards on programming best practices, Highlight implements hundreds of code insights across 15+ technologies to calculate health factors of a software.