JS Daily 19 - Optional Chaining

Last updated on 8 Dec, 2020

What is the output of following code?

const obj = {
  a: false


The output is TypeError. It says TypeError: obj.a is not a function.

Optional Chaining operator checks for only null or undefined on the left hand side. In this case a has the value false. So optional chaining operator continues chaining and it results in calling a function like false(). That results in TypeError.

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Joby Joseph
Web Architect