Check if a Specific Key is present in Swift Dictionary

Swift – Check if Specific Key is Present in Dictionary

Welcome to Swift Tutorial. In this tutorial, we will learn how to check if a specific key is present a Swift Dictionary.

To check if a specific key is present in a Swift dictionary, check if the corresponding value is nil or not.

let keyExists = myDictionary[key] != nil

If myDictionary[key] != nil returns true, the key is present in this dictionary, else the key is not there.

You can assign the result to a variable like keyExists in the above syntax, and use for any other conditional checks.

Example 1 – Check if Key is not present in Swift Dictionary

In this example, we shall create a dictionary with some initial values and try to check if a new key is present in the dictionary or not.

main.swift

var myDictionary:[String:Int] = ["Mohan":75, "Raghu":82, "John":79]

let keyExists = myDictionary["Surya"] != nil

if keyExists{
    print("The key is present in the dictionary")
} else {
    print("The key is not present in the dictionary")
}

Output

The key is not present in the dictionary

Example 2 – Check if Key is present in Swift Dictionary

In this example, we shall take a dictionary with some initial values and try to check if an existing key is present in the dictionary or not.

main.swift

var myDictionary:[String:Int] = ["Mohan":75, "Raghu":82, "John":79]

let keyExists = myDictionary["John"] != nil

if keyExists{
    print("The key is present in the dictionary")
} else {
    print("The key is not present in the dictionary")
}

Output

The key is present in the dictionary

Conclusion

In this Swift Tutorial, we have learned how to check if a specific key is present in a Swift Dictionary with the help of example programs.