import Foundation
let pattern = #"\d_([a-zA-Z_]+)_[0-9]+_"#
let regex = try! NSRegularExpression(pattern: pattern)
let testString = #"""
abc_account2621_activity_20161116_20161117_030627_311999667.csv
abc_account2621_click_2016111606_20161116_221031_311735299.csv
abc_account2621_impression_2016111605_20161116_221808_311685411.csv
abc_account2621_rich_media_2016111606_20161116_192542_311735300.csv
abc_account2621_match_table_actwd342ivity_cats_20161116_20161117_0311_31.csv.gz
abc_account2621_match_table_activity_tdwypes_20161116_20161117_0342_31.csv.gz
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression