What does 2 exclamation marks mean in Kotlin?

AndroidMobile DevelopmentApps/ApplicationsKotlin. In Kotlin, “!!” is an operator that is known as the double-bang operator . This operator is also known as “not-null assertion operator”. This operator is used to convert any value to a non-NULL type value and it throws an exception if the corresponding value is NULL.

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What is unit type in Kotlin?

The Unit type is what you return from a function that doesn’t return anything of interest . Such a function is usually performing some kind of side effect. The unit type has only one possible value, which is the Unit object. You use Unit as a return type in Kotlin when you would use void (lowercase v) in Java.

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