What is the purpose of the 'in' operator in programming?

The in operator in programming is typically used to check for membership of an element in a collection or range. For example, in Kotlin (commonly used in Android development), the in operator checks whether an element is contained within a range or collection:

val x = 5
if (x in 1..10) {
    println("Number $x is in the range from 1 to 10")
}

Here, x in 1..10 checks whether the value of x is within the inclusive range from 1 to 10. Similarly, in can be used to check for the presence of an element in a list or array.