Reading from Standard Input

In this lesson you will learn how to read standard input with readLine in Kotlin, so your program can respond to what a user types. This is for anyone searching for "Kotlin readLine how to use".

readLine() reads one line of input from the keyboard or another source. Use it when a command-line tool needs the user to type something.

The sample code prompts without a newline using print("Enter your name: "), reads what was typed into name with readLine(), and uses it in a greeting.

A common stumbling block for beginners is that readLine() returns a nullable type. It does so out of null safety, so you need to understand the difference between using it directly and checking for null first.

In real-world development, using input without validating it can lead to unexpected errors, so pairing it with a validation step is safer.