Trusted answers to developer questions
What is array.firstIndex(of:) in Swift?
Theodore Kelechukwu OnyejiakuOverview
The firstIndex(of:) method is used to return the first index of a specified array element.
Syntax
arr.firstIndex(of: element)
Parameters
element: The element to search for in the array or collection.
Return value
This method returns the first index where the element is found. If the element is not found, nil is returned.
Example
// create arrays let evenNumbers = [2, 4, 6, 8, 10] let twoLetterWords = ["up", "go", "me", "we"] let names = ["John", "James", "Theodore"] // get index of some elements let result1 = evenNumbers.firstIndex(of : 4)! let result2 = twoLetterWords.firstIndex(of: "go")! let result3 = names.firstIndex(of: "Theodore")! // print results print(result1) print(result2) print(result3)
Getting the index of elements specified
Explanation
- Lines 2 and 3: We create some arrays.
- Lines 7 to 9: We get the index of the elements specified using the
firstIndex(of:)method. And we store the results in some variables. - Lines 12 to 14: We print our results.
RELATED TAGS
array
swift
index
communitycreator
CONTRIBUTOR
Theodore Kelechukwu OnyejiakuRELATED COURSES
View all Courses
Keep Exploring
Related Courses
