Mastering Kotlin Essentials/

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Map Operations

Map Operations

Explore essential map operations, including checking for key existence, determining map size, iterating through maps, and working with mutable maps.

We'll cover the following...

Checking if a map contains a key

We can check if our map contains a key using the in keyword or the containsKey method.

Kotlin 1.5
fun main() {
    val map = mapOf('A' to "Alex", 'B' to "Bob")
    println('A' in map) // true
    println(map.containsKey('A')) // true
    println('Z' in map) // false
    println(map.containsKey('Z')) // false
}

Checking map size

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