How to Get the Value Associated with a Key in a Dictionary in Swift - Step by Step Examples

How to Get the Value Associated with a Key in a Dictionary in Swift ?

Answer

To get the value associated with a key in a dictionary in Swift, you can use the subscript syntax or the `Dictionary`'s `get` method with optional binding to handle cases where the key might not exist.

✐ Examples

1 Getting the Value Associated with a Key Using Subscript Syntax

We can get the value associated with a key in a dictionary in Swift using the subscript syntax. This example demonstrates how to retrieve the value for a specific key and print it.

For example,

We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
We use the subscript syntax to get the value associated with a key.
We print the value associated with the key.

Swift Program

var myDictionary: [Int: String] = [
    1: "One",
    2: "Two",
    3: "Three"
]

// Key to get the value for
let keyToGet = 2

// Get the value associated with the key
if let value = myDictionary[keyToGet] {
    print("The value associated with key \(keyToGet) is '\(value)'.")
} else {
    print("The key \(keyToGet) does not exist in the dictionary.")
}

Output

The value associated with key 2 is 'Two'.

2 Getting the Value Associated with a Key Using Optional Binding

We can get the value associated with a key in a dictionary in Swift using optional binding with `if let`. This example demonstrates how to safely retrieve the value for a specific key and print it if it exists.

For example,

We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
We use optional binding to get the value associated with a key.
We print the value associated with the key if it exists, or a message if it does not.

Swift Program

var myDictionary: [Int: String] = [
    1: "One",
    2: "Two",
    3: "Three"
]

// Key to get the value for
let keyToGet = 4

// Try to get the value associated with the key using optional binding
if let value = myDictionary[keyToGet] {
    print("The value associated with key \(keyToGet) is '\(value)'.")
} else {
    print("The key \(keyToGet) does not exist in the dictionary.")
}

Output

The key 4 does not exist in the dictionary.

Summary

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

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How to Get the Value Associated with a Key in a Dictionary in Swift - Step by Step Examples