TypeScript Tutorials

How to Get the Value Associated with a Key in a Map in TypeScript

How to Get the Value Associated with a Key in a Map in TypeScript ?

Answer

To get the value associated with a key in a map in TypeScript, you can use the get method. This method allows you to access the value directly using the key.

✐ Examples

1 Getting the Value Associated with a Key Using get Method

We can get the value associated with a key in a map in TypeScript using the get method, which returns the value associated with the specified key.

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 use the get method to access the value associated with the key 'two'. The get method returns the value associated with the specified key.
We store the value in a variable named value.
We print the value to the console using the console.log function.

TypeScript Program

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

// Get the value associated with a key using get method
const value = myMap.get('two');

// Print the value
console.log(`The value associated with key 'two' is: ${value}`);

Output

The value associated with key 'two' is: 2

2 Handling Key Not Found Using get Method

We can handle the case where a key is not found in a map in TypeScript using the get method, which returns undefined if the key is not present.

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 use the get method to attempt to access the value associated with the key 'four'. The get method returns undefined if the key is not found.
We store the value in a variable named value.
We check if the value is undefined and print an appropriate message to the console using the console.log function.

TypeScript Program

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

// Attempt to get the value associated with a non-existent key
const value = myMap.get('four');

// Print the result
if (value === undefined) {
    console.log('Key "four" not found in the map.');
} else {
    console.log(`The value associated with key 'four' is: ${value}`);
}

Output

Key "four" not found in the map.

3 Getting Multiple Values Using get Method

We can get multiple values associated with keys in a map in TypeScript using the get method, which returns the value associated with each key.

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 use the get method to access the values associated with the keys 'one' and 'four'. The get method returns the value associated with each key.
We store the values in variables named valueOne and valueFour.
We print the values to the console using the console.log function. If a key is not found, the corresponding value will be undefined.

TypeScript Program

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

// Get the values associated with keys 'one' and 'four' using get method
const valueOne = myMap.get('one');
const valueFour = myMap.get('four');

// Print the values
console.log(`The value associated with key 'one' is: ${valueOne}`);
console.log(`The value associated with key 'four' is: ${valueFour}`);

Output

The value associated with key 'one' is: 1
The value associated with key 'four' is: undefined

Summary

In this tutorial, we learned How to Get the Value Associated with a Key in a Map in TypeScript language with well detailed examples.

◀ Previous Next ▶

TypeScript Tutorials

TypeScript How-Tos

How to Get the Value Associated with a Key in a Map in TypeScript