Collin Rusk
Sep 4, 2018 · 1 min read

The rule that states that let should be used instead of var will not work, if the JavaScript has to run on legacy browsers, which doe not support the let keyword. The same is true for arrow functions. For consumer software such as Facebook or Google, restriction to newer browsers is not typically a hindrance. Such a restriction is a hindrance for enterprise software, which is frequently legacy software. Much of this software is designed for older browsers, particularly older versions of IE. There is a good reason to still use var: backward compatibility.

    Collin Rusk

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    Software Architect with a specialty in enterprise systems and a broad collection of interests