RegEx

Regex Tester for JavaScript
Regular Expressions in Java
Java Regex Tutorial by Lars Vogel

Info: JavaScript

1 2	var matches = json.match(/REGEX/); // Beendet nach dem ersten Fund var matches = json.match(/REGEX/g); // Durchsucht bis zum Ende

See: Regular Expressions in JavaScript, part 2
i // ignore case // uppercase and lowercase will be ignored
g // global search // the search is carried out across the entire string
m // multiline search // the regular expression will match over multiple lines

Capturing and non-capturing groups

Capturing groups

var string = '1st,2nd,3rd,4th';
var matches = string.match(/([0-9]+)(st|nd|rd|th)/g);
console.log(matches); // ["1st", "2nd", "3rd", "4th"]
var replaces = string.replace(/([0-9]+)(st|nd|rd|th)/g,'$1');
console.log(replaces); // 1,2,3,4

Die Gruppen (...) bilden Captures.
([0-9]+) ist Capture 1 ($1)
(st|nd|rd|th) ist Capture 2 ($2)

Non-capturing groups

Möchte man ([0-9]+) vom Capturing ausschließen, so muss man eine non-capturing group daraus machen. Das geht mit (?:[0-9]+).

Beispiel:

var string = '1st,2nd,3rd,4th';
var matches = string.match(/([0-9]+)(st|nd|rd|th)/g);
console.log(matches); // ["1st", "2nd", "3rd", "4th"]
var replaces = string.replace(/(?:[0-9]+)(st|nd|rd|th)/g,'$1');
console.log(replaces); // st,nd,rd,th

Match word in a sentence

var sentence = 'The internet browser Mozilla Firefox awesome.';
var match = sentence.match(/(Firefox)/)[0];
document.write(match); // Firefox

Pattern pattern = Pattern.compile("(Firefox)");
Matcher matcher = pattern.matcher("The internet browser Mozilla Firefox awesome.");
matcher.find();
System.out.println(matcher.group(0)); // Firefox

Match sentence with two words

var sentence = 'I like the Mozilla Firefox browser.';
var match = sentence.match(/.*(Mozilla).*(Firefox).*/)[0];
document.write(match); // I like the Mozilla Firefox browser.

Pattern pattern = Pattern.compile(".*(Mozilla).*(Firefox).*");
Matcher matcher = pattern.matcher("I like the Mozilla Firefox browser.");
matcher.find();
System.out.println(matcher.group(0)); // I like the Mozilla Firefox browser.

Match everything after the first comma (Explanation)

var sentence = 'Match everything, after the first comma.';
var match = sentence.match(/,.*$/)[0];
document.write(match); // , after the first comma.

Pattern pattern = Pattern.compile(",.*$");
Matcher matcher = pattern.matcher("Match everything, after the first comma.");
matcher.find();
System.out.println(matcher.group(0)); // , after the first comma.

Match everything after the last comma (Explanation)

var sentence = 'Match everything, after the last comma, hihi.';
var match = sentence.match(/[^,]*$/)[0];
document.write(match); // hihi.

Pattern pattern = Pattern.compile("[^,]*$");
Matcher matcher = pattern.matcher("Match everything, after the last comma, hihi.");
matcher.find();
System.out.println(matcher.group(0)); //  hihi

Match everything when it does not contain a certain word (Explanation)

var sentence = 'I like pizza too much.';
var match = sentence.match(/^((?!pizza).)*$/);
document.write(match); // null

Pattern pattern = Pattern.compile("^((?!pizza).)*$");
Matcher matcher = pattern.matcher("I like pizza too much.");
matcher.find();
System.out.println(matcher.group(0)); // java.lang.IllegalStateException: No match found

Match everything after a certain word

var url = 'www.bennyn.de';
var match = url.match(/[^www.].*/)[0];
document.write(match); // bennyn.de

Pattern pattern = Pattern.compile("[^www.].*");
Matcher matcher = pattern.matcher("www.bennyn.de");
matcher.find();
System.out.println(matcher.group(0)); // bennyn.de

Match everything until a certain character

var sentence = 'The dot is missing.';
var match = sentence.match(/.*?(?=\.)/)[0];
document.write(match); // The dot is missing

Pattern pattern = Pattern.compile(".*?(?=\\.)");
Matcher matcher = pattern.matcher("The dot is missing.");
matcher.find();
System.out.println(matcher.group(0)); // The dot is missing

Match domain in an URL

var url = 'http://angelcode.de:3000/room/e0e669ac5fe7ca5';
var match = url.match(/[^http:\/\/].*?(?=:)/)[0];
document.write(match); // angelcode.de

Pattern pattern = Pattern.compile("[^http:\\/\\/].*?(?=:)");
Matcher matcher = pattern.matcher("http://angelcode.de:3000/room/e0e669ac5fe7ca5");
matcher.find();
System.out.println(matcher.group(0)); // angelcode.de

Match arbitrary ending / match everything that begins with /

const url = "https://api.binance.com/api/v3/account?timestamp=1520550477929&signature=123"
const pattern = /https:\/\/api\.binance\.com\/api\/v3\/account.*$/
const matching = url.match(pattern)[0]