How to run a case-insensitive search for one string inside another
Swift version: 5.4
You can search for one string inside another using the range(of:) method, like this:
let string = "The rain in Spain"
let range1 = string.range(of: "rain")That returns an optional string index: if the word was found it will say where it was found, otherwise it will be nil.
However, range(of:) does a case-sensitive search by default, which means it will match “rain” but not “Rain” or “RAIN”. If you want a case-insensitive search you need to provide an extra parameter called options, passing it .caseInsensitive:
let range2 = string.range(of: "rain", options: .caseInsensitive)That returns the same optional value depending on what was found, so you can wrap the whole thing in an if let to see whether a match was found:
if let range3 = string.range(of: "rain", options: .caseInsensitive) {
// match
} else {
// no match
}
SPONSORED From August 2nd to 8th you can join a FREE crash course for mid/senior iOS devs who want to achieve an expert level of technical and practical skills – it’s the fast track to being a complete senior developer!
Sponsor Hacking with Swift and reach the world's largest Swift community!
Available from iOS 8.0
Similar solutions…
- How to convert between camel case and snake case with Codable and keyEncodingStrategy
- How to use UISearchController to let users enter search words
- How to add a search bar to filter your data
- How to find similar words for a search term
- How to force one gesture to recognize before another using highPriorityGesture()
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
