Why you should care
Although JavaScript allows to declare multiple variables in a single chain, it is recommended to declare each variable separately as it is easier to read and reduce the risk of unexpected behaviors in some cases.
How we detect
CAST Highlight counts one occurrence when multiple variable declarations are detected.
Bad Code
var header, topnav, content;
Good Code
var firstVar; var secondVar; var thirdVar;
References
https://eslint.org/docs/rules/one-var
https://bluepnume.medium.com/theres-no-need-to-define-all-javascript-vars-once-at-the-top-of-a-function-and-there-hasn-t-been-a66b31f21822
https://bluepnume.medium.com/theres-no-need-to-define-all-javascript-vars-once-at-the-top-of-a-function-and-there-hasn-t-been-a66b31f21822
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.