How to Remove Key-Value Pairs from a Map Based on Values in Kotlin - Step by Step Examples

How to Remove Key-Value Pairs from a Map Based on Values in Kotlin ?

Answer

To remove key-value pairs from a map in Kotlin based on values, you need to iterate through the map and check each value. If the value matches the specified condition, remove the corresponding key-value pair.

✐ Examples

1 Removing Key-Value Pairs with Specific Value

We can remove key-value pairs from a map in Kotlin by iterating through the map and removing pairs with a specific value.

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 iterate through the map using the entries property and the removeIf method on the map's entry set. For each key-value pair, we check if the value matches the specified value 2.
If the value matches, the removeIf method removes the key-value pair from the map.
We print the contents of the map to the console using the println function to verify that the key-value pairs have been removed.

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,
        "four" to 2
    )

    // Remove key-value pairs with specific value
    myMap.entries.removeIf { it.value == 2 }

    // Print the contents of the map
    println(myMap)
}

Output

{one=1, three=3}

2 Removing Key-Value Pairs with a Range of Values

We can remove key-value pairs from a map in Kotlin by iterating through the map and removing pairs with values within a specified range.

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 iterate through the map using the entries property and the removeIf method on the map's entry set. For each key-value pair, we check if the value falls within the specified range (e.g., between 2 and 3 inclusive).
If the value falls within the range, the removeIf method removes the key-value pair from the map.
We print the contents of the map to the console using the println function to verify that the key-value pairs have been removed.

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,
        "four" to 4
    )

    // Remove key-value pairs with values in the range [2, 3]
    myMap.entries.removeIf { it.value in 2..3 }

    // Print the contents of the map
    println(myMap)
}

Output

{one=1, four=4}

3 Removing Key-Value Pairs with Condition-Based Values

We can remove key-value pairs from a map in Kotlin by iterating through the map and removing pairs with values that meet a specified condition.

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 string values.
We iterate through the map using the entries property and the removeIf method on the map's entry set. For each key-value pair, we check if the value meets a specified condition (e.g., if the length of the string is 3).
If the condition is met, the removeIf method removes the key-value pair from the map.
We print the contents of the map to the console using the println function to verify that the key-value pairs have been removed.

Kotlin Program

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

    // Remove key-value pairs where value length is 3
    myMap.entries.removeIf { it.value.length == 3 }

    // Print the contents of the map
    println(myMap)
}

Output

{three=three, four=four}

Summary

In this tutorial, we learned How to Remove Key-Value Pairs from a Map Based on Values in Kotlin language with well detailed examples.

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How to Remove Key-Value Pairs from a Map Based on Values in Kotlin - Step by Step Examples