How to check if an environment variable is set in Node.js?

Spread the love

To check if an environment variable is set in Node.js, we use the in operator.

For instance, we write

if ("DEBUG" in process.env) {
  console.log(process.env.DEBUG);
} else {
  console.log("Env var IS NOT SET");
}

to check if the DEBUG property is in process.env with "DEBUG" in process.env to check if the DEBUG environment variable is set.

By John Au-Yeung