As mentioned in Kotlin API document, readLine() returns the line read or null if end of file has already been reached but it is the same functionality as readlnOrNull(). So what is the difference here?
I know that readlnOrNull() and readln() have been introduced in Kotlin 1.6 for the purpose of null safety but I can’t understand why readlnOrNull() introduced when readLine() exist before.
>Solution :
They added readlnOrNull as an alias of readLine for the sake of preserving the convention that each standard library function that throws a RuntimeException has an “orNull” version that returns null instead of throwing. It was added when readlnwas added. It’s so the matching function with this behavior can be easily found. If readLn had existed from the earliest version of Kotlin, then they might never have created a redundant readLine function that matches the behavior of readlnOrNull. They have not deprecated readLine because there’s nothing wrong with its behavior and it’s concise.