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

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

Answer

To remove key-value pairs from a map in TypeScript 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 TypeScript by iterating through the map and removing pairs with a specific value.

For example,

We start by declaring and initializing a 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 a for...of loop. For each key-value pair, we check if the value matches the specified value 2.
If the value matches, we use the delete method to remove the key-value pair from the map.
We print the contents of the map to the console using the console.log function to verify that the key-value pairs have been removed.

TypeScript Program

const myMap: Map<string, number> = new Map([
    ['one', 1],
    ['two', 2],
    ['three', 3],
    ['four', 2]
]);

// Remove key-value pairs with specific value
for (const [key, value] of myMap) {
    if (value === 2) {
        myMap.delete(key);
    }
}

// Print the contents of the map
console.log(myMap);

Output

Map(2) { 'one' => 1, 'three' => 3 }

2 Removing Key-Value Pairs with a Range of Values

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

For example,

We start by declaring and initializing a 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 a for...of loop. 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, we use the delete method to remove the key-value pair from the map.
We print the contents of the map to the console using the console.log function to verify that the key-value pairs have been removed.

TypeScript Program

const myMap: Map<string, number> = new Map([
    ['one', 1],
    ['two', 2],
    ['three', 3],
    ['four', 4]
]);

// Remove key-value pairs with values in the range [2, 3]
for (const [key, value] of myMap) {
    if (value >= 2 && value <= 3) {
        myMap.delete(key);
    }
}

// Print the contents of the map
console.log(myMap);

Output

Map(2) { 'one' => 1, 'four' => 4 }

3 Removing Key-Value Pairs with Condition-Based Values

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

For example,

We start by declaring and initializing a 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 a for...of loop. 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, we use the delete method to remove the key-value pair from the map.
We print the contents of the map to the console using the console.log function to verify that the key-value pairs have been removed.

TypeScript Program

const myMap: Map<string, string> = new Map([
    ['one', 'one'],
    ['two', 'two'],
    ['three', 'three'],
    ['four', 'four']
]);

// Remove key-value pairs where value length is 3
for (const [key, value] of myMap) {
    if (value.length === 3) {
        myMap.delete(key);
    }
}

// Print the contents of the map
console.log(myMap);

Output

Map(2) { 'three' => 'three', 'four' => 'four' }

Summary

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

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