--- title: Use the .env File --- ## Use the .env File We can use the .toUpperCase() method to make a string all caps, such as: ```javascript var response = "Hello World".toUpperCase(); // now becomes "HELLO WORLD" ``` All we need to do now is check what the value of the environment variable is, which you can do like: ```javascript if (process.env.VAR_NAME === "allCaps") { resonse = "Hello World".toUpperCase(); } else { response = "Hello World"; } }); ``` Help our community expand these hints and guides.