Trim. Often strings contain whitespace (like spaces or newlines) at their starts or ends. These characters are often removed or trimmed.
In Foundation, using Swift 5.8, we can access a method called trimmingCharacters. A character set is required. The result is a string with the specified characters removed.
An example. Let us begin with a simple example. We introduce a "source" string that contains a leading space, and a trailing period and space.
Start We create a CharacterSet with 3 characters—a space, period, and a question mark.
Next We invoke the trim method, trimmingCharacters. We pass the set instance as an argument.
Result The string returned has no leading or trailing spaces (and no period).
// The string we are trimming.
let source = " Programming in Swift. "// Create a character set of chars to trim.
let set = CharacterSet(charactersIn: " .?")
// Call func with character set.
let result = source.trimmingCharacters(in: set)
// Write the result.
print(result)Programming in Swift
An alternative. A custom pair of loops (for startIndex and endIndex) could be written. In these, we continue towards the center of a string as removable characters are encountered.
Then We take a substring (of the inner part of the string) to perform the trimming operation.