Created
June 2, 2017 09:01
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Swift 3 String substring extension for easier handling if offset exceeds endIndex
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| extension String { | |
| /// Returns a new string containing the characters of the String from the one at a given index to the end. If 'from' exceeds endIndex it returns an empty string. | |
| func substring(from: Int) -> String { | |
| guard let offsetStartIndex = index(startIndex, offsetBy: from, limitedBy: endIndex) else { return "" } | |
| return self[offsetStartIndex..<endIndex] | |
| } | |
| /// Returns a new string containing the characters of the String up to the one at a given index. If 'to' exceeds endIndex it returns the string as it was. | |
| func substring(to: Int) -> String { | |
| return self[startIndex..<(index(startIndex, offsetBy: to, limitedBy: endIndex) ?? endIndex)] | |
| } | |
| /// Returns a string object containing the characters of the String that lie within a given range. If 'from' exceeds endIndex it returns an empty string. If 'to' exceeds endIndex it returns the string from 'from' to endIndex. | |
| func substring(from: Int, to: Int) -> String { | |
| guard let offsetStartIndex = index(startIndex, offsetBy: from, limitedBy: endIndex) else { return "" } | |
| guard let offsetEndIndex = index(startIndex, offsetBy: to, limitedBy: endIndex) else { return self[offsetStartIndex..<endIndex] } | |
| return self[offsetStartIndex..<offsetEndIndex] | |
| } | |
| } |
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