Swift:
Searching and replacing text
How to:
var greetings = "Hello, old friend!"
// Simple replace
greetings = greetings.replacingOccurrences(of: "old", with: "new")
print(greetings) // "Hello, new friend!"
// Using options for case-insensitive replace
let caseInsensitiveResult = greetings.replacingOccurrences(
of: "hello",
with: "Hi",
options: .caseInsensitive
)
print(caseInsensitiveResult) // "Hi, new friend!"
// Replacing with regular expressions
let regexResult = greetings.replacingOccurrences(
of: "\\bnew\\b",
with: "best",
options: .regularExpression
)
print(regexResult) // "Hello, best friend!"Deep Dive
We’ve been swapping text in strings since the early days of computing. Initially, it was with simple command-line tools like sed. In Swift, replacingOccurrences(of:with:) does the heavy lifting, and you get more control with options like .caseInsensitive or .regularExpression.
Alternatives in Swift include using NSRegularExpression for complex patterns and NSMutableString for mutable string operations. Under the hood, Swift’s string replacement methods bridge to powerful Objective-C counterparts, providing speed and versatility.