How to Check if a Map is Empty in Kotlin

How to Check if a Map is Empty in Kotlin ?

Answer

To check if a map is empty in Kotlin, you can use the isEmpty method. This method returns a boolean value indicating whether the map contains any elements.

✐ Examples

1 Checking if a Map is Empty Using isEmpty Method

We can check if a map is empty in Kotlin using the isEmpty method, which returns true if the map contains no elements and false otherwise.

For example,

We start by declaring and initializing an empty mutable map named myMap. In this example, the map has string keys and integer values.
We use the isEmpty method to check if the map is empty. The isEmpty method returns a boolean value indicating whether the map contains any elements.
We print the result to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize an empty mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf()

    // Check if the map is empty using isEmpty method
    val isEmpty = myMap.isEmpty()

    // Print the result
    println("Is the map empty? $isEmpty")
}

Output

Is the map empty? true

2 Checking if a Non-Empty Map is Empty Using isEmpty Method

We can check if a non-empty map is empty in Kotlin using the isEmpty method, which returns false if the map contains elements.

For example,

We start by declaring and initializing a mutable map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the isEmpty method to check if the map is empty. The isEmpty method returns a boolean value indicating whether the map contains any elements.
We print the result to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize a mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Check if the map is empty using isEmpty method
    val isEmpty = myMap.isEmpty()

    // Print the result
    println("Is the map empty? $isEmpty")
}

Output

Is the map empty? false

3 Checking if a Map is Empty After Clearing Using isEmpty Method

We can check if a map is empty in Kotlin after clearing its elements using the isEmpty method, which returns true if the map contains no elements.

For example,

We start by declaring and initializing a mutable map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
We use the clear method to remove all elements from the map, making it empty.
We use the isEmpty method to check if the map is empty after clearing. The isEmpty method returns a boolean value indicating whether the map contains any elements.
We print the result to the console using the println function.

Kotlin Program

fun main() {
    // Declare and initialize a mutable map
    val myMap: MutableMap<String, Int> = mutableMapOf(
        "one" to 1,
        "two" to 2,
        "three" to 3
    )

    // Clear the map
    myMap.clear()

    // Check if the map is empty using isEmpty method
    val isEmpty = myMap.isEmpty()

    // Print the result
    println("Is the map empty? $isEmpty")
}

Output

Is the map empty? true

Summary

In this tutorial, we learned How to Check if a Map is Empty in Kotlin language with well detailed examples.

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