How do I check if a string contains another string in Swift?

nsstring, string, substring, swift

Solution

You can do exactly the same call with Swift:

Swift 4 & Swift 5

In Swift 4 String is a collection of `Character` values, it wasn't like this in Swift 2 and 3, so you can use this more concise code1:

let string = "hello Swift"
if string.contains("Swift") {
    print("exists")
}

Swift 3.0+

var string = "hello Swift"

if string.range(of:"Swift") != nil { 
    print("exists")
}

// alternative: not case sensitive
if string.lowercased().range(of:"swift") != nil {
    print("exists")
}

Older Swift

var string = "hello Swift"

if string.rangeOfString("Swift") != nil{ 
    println("exists")
}

// alternative: not case sensitive
if string.lowercaseString.rangeOfString("swift") != nil {
    println("exists")
}

I hope this is a helpful solution since some people, including me, encountered some strange problems by calling `containsString()`.1

PS. Don't forget to `import Foundation`

Footnotes

- Just remember that using collection functions on Strings has some edge cases which can give you unexpected results, e. g. when dealing with emojis or other grapheme clusters like accented letters.

Problem

In `Objective-C` the code to check for a substring in an `NSString` is: ``` NSString *string = @"hello Swift"; NSRange textRange =[string rangeOfString:@"Swift"]; if(textRange.location != NSNotFound) { NSLog(@"exists"); } ``` But how do I do this in Swift?

Original source