Swift Tutorials

How to Check if a Value Exists in a Dictionary in Swift

How to Check if a Value Exists in a Dictionary in Swift ?

Answer

To check if a value exists in a dictionary in Swift, you can use the `contains` method on the dictionary's `values` property. This allows you to check for the presence of a value in a dictionary.

✐ Examples

1 Checking if a Value Exists Using the `contains` Method

We can check if a value exists in a dictionary in Swift using the `contains` method on the `values` property. This example demonstrates how to check for the presence of a value and print a message based on the result.

For example,

We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
We use the `contains` method on the `values` property to check if a value exists in the dictionary.
We print a message based on whether the value exists or not.

Swift Program

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

// Value to check
let valueToCheck = "Two"

// Check if the value exists using the contains method
if myDictionary.values.contains(valueToCheck) {
    print("Value '(valueToCheck)' exists in the dictionary.")
} else {
    print("Value '(valueToCheck)' does not exist in the dictionary.")
}

Output

Value 'Two' exists in the dictionary.

2 Checking if a Value Does Not Exist Using the `contains` Method

We can check if a value does not exist in a dictionary in Swift using the `contains` method on the `values` property. This example demonstrates how to check for the absence of a value and print a message based on the result.

For example,

We start by declaring and initializing a dictionary named myDictionary with integer keys and string values.
We use the `contains` method on the `values` property to check if a value does not exist in the dictionary.
We print a message based on whether the value exists or not.

Swift Program

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

// Value to check
let valueToCheck = "Four"

// Check if the value does not exist using the contains method
if !myDictionary.values.contains(valueToCheck) {
    print("Value '(valueToCheck)' does not exist in the dictionary.")
} else {
    print("Value '(valueToCheck)' exists in the dictionary.")
}

Output

Value 'Four' does not exist in the dictionary.

Summary

In this tutorial, we learned How to Check if a Value Exists in a Dictionary in Swift language with well detailed examples.

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How to Check if a Value Exists in a Dictionary in Swift