(?:https?\:|^|\s) - non-capturing group. It matches but does not capture a substring that is preceded by one of the following: https, http, start of string (^), a whitespace character (\s). The last two items are included to handle protocol-relative URLs like "//google.com". \...
One more way to match a substring in square brackets is to use anegation operator(^) inside the capturing group. From the first opening bracket, this pattern captures any characters other than a closing bracket, until it finds the first closing bracket. The result will be the same as with ...
validating forms, extracting a substring from a string based on a pattern match, and so much more. The term "regular expression" is a mouthful, so you will usually find the term abbreviated to "regex" or "regexp". Imagine you are writing an application and you want to set the rules f...
I then create the string that I’m going to replace; I give this string the variable name initial. After that, I create a format string that specifies what I want to do with the substrings that match. Just to demonstrate what’s happening, I’m simply copying the matched substring, but...
正则表达式(Regular Expression)是一种文本模式。它使用单个字符串来描述、匹配一系列匹配某个句法规则的字符串。正则表达式在代码中也有regex,regexp,RE 等形式。总之,正则表达式就是通过一个符合某种形式的字符串去匹配另一个字符串中符合某种规则的子字符串(substring)。正则表达式在Java中的使...
一种方法是从目标词开始开始模式，并使用lookarounds来捕捉前后的文本（或单词）：使用“尽可能多的重复...
The common substring function most people use is: substring(string,start_position,length) which can also be written as substring(stringFROMstart_positionFORlength) With thelengthandFORlengthclause being optional and when left out giving you the string from the start position to the end of string....
Regular expressions are used to replace text within a string, validate forms, extract a substring from a string based on a pattern match, and so much more. The term "regular expression" is a mouthful, so you will usually find the term abbreviated to "regex" or "regexp"....
一种方法是从目标词开始开始模式，并使用lookarounds来捕捉前后的文本（或单词）：使用“尽可能多的重复...
[]) let nsString = text as NSString let results = regex.matchesInString(text, options: [], range: NSMakeRange(0, nsString.length)) return results.map { nsString.substringWithRange($0.range)} } catch let error as NSError { print("invalid regex: \(error.localizedDescription)") return ...