Regular Expressions 101

Save & Share

  • Regex Version: ver. 1
  • Update Regex
    ctrl+⇧+s
  • Save new Regex
    ctrl+s
  • Add to Community Library

Flavor

  • PCRE2 (PHP >=7.3)
  • PCRE (PHP <7.3)
  • ECMAScript (JavaScript)
  • Python
  • Golang
  • Java 8
  • .NET 7.0 (C#)
  • Rust
  • Regex Flavor Guide

Function

  • Match
  • Substitution
  • List
  • Unit Tests

Tools

Sponsors
There are currently no sponsors. Become a sponsor today!
An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

// include the latest version of the regex crate in your Cargo.toml extern crate regex; use regex::Regex; fn main() { let regex = Regex::new(r"(?m)^[a-z\d]+(\-[a-z\d]+){0,7}$").unwrap(); let string = "zerox wtech 001-game-creator 2d-fighter-maker-2nd 2d-rts-multiplayer-engine 2devolved 2dream 2moons 3d-engine-gepard 3d-rad 3dge 3dstate 3dvia-studio 3dzzd 3impact 4a-engine 9gears adaptive-game-engine-age adobe-director adobe-flash-professional advengen adventure-game-studio adventure-maker affinity-engine agar age age1 age-3d agen agharta-studio-engine airnovel akari3d-engine alamo aleph-one alicesoft-system-40 allbinary-platform altengine ambrose3d amp2 andengine angry-turtle anime-studio annihilation-engine-for-source antiryad-gx scimitar apexcmd apocalyx app-game-kit apricotjs aqua archive-games argon-4 articx aspen astrogame-engine aura aura-engine aurora-engine away3d axis axis-game-factory aztica-6dx babylonjs backbone-game-engine bacon2d bang-engine barok barrage-engine base-render-unit-engine bennugd biengine big-world-technology bit-engine bitsquid bittech black-sun-engine blackion-game-engine blade3d blanke blast3d blender-game-engine blitwizard blitz-max blockygame-engine bloxel box2d brahma brender brfactory bright-engine broken-mug-engine btengine build build2 c3d cafu-engine calidus cardboard-engine carnivorous-exports castle-game-engine cellblock-9 cgda-computer-game-development-architecture chrome-engine-1 chrome-engine-2 chrome-engine-3 chrome-engine-4 chrome-engine-5 chrome-engine-6 cine-engine clausewitz-engine cloacknt-engine cloaknt clockwork-engine cloudbuilder cmv-3d cocos2d-for-iphone cocos2d-x collapsed-engine colyseus commandos-engine concept-2d construct construct-2 construct-3 coppercube core corengine corona corrinoengine cortex corus-engine corvus-engine cosmic-engine covertengine cpal3d-engine cr-editor craftstudio crazy-engine creation-engine crimson-engine crowdcore-engine crybits cryengine cryengine-2 cryengine-3 cryengine-v crystal-dynamics-engine crystalspace-3d ctech-25d cube cube-2 cumulonimbus-engine custom-built cyclone-engine daedalus daemon dagmen-engine dagon dagor dark-engine dark-tech darkbasic-professional darkplaces-engine defold demon-tactic-engine diasphere diesel-engine digital-dream-engine dim3-dimension-3 dingo-engine directd3x-75 div-go-games-online doom-engine doom dotnettorque dotworldmaker dragengine dragans-games-inhouse-engine dragonov3d dragonsource dragora-framework dream-maker dsk duality dungeons-3d dunia dust dx-studio e-kfuture-engine epic e2d-engine easy3d eclipse eclipse-evolution eclipse-origins eclipse-skywyre-2d-orpg-maker eduke32 ees eg-3d-game-engine egdk-engine ego-game-technology-engine eternallove-engine electric element-games-engine emily-is-away empowered-creation-kit enginex enigma-development-environment enigma-engine enin-engine environ epsilon essence-engine eternal-tech ethanon etna-2d-gameengine-net europa-engine ev-va-engine existence-2 exotic-matter-engine extreme-motion ezengine f2b-engine fastbird-engine fenix fire-frost-2d first-frost first-flight flashpunk flashugee flatredball flax fle-game-engine fife flight-deck-ge flight-engine flixel flowlab flux-engine fonline-engine forgelight-engine fox-engine foxhound-engine fps-creator-x10 fpsc free-heroes-of-might-and-magic-ii-resurrection free-libre-action-roleplaying-engine freebasic frostbite frostbite-2 frostbite-3 fs2-open-engine fte-quakeworld fusee game-develop1 game-develop game-development-suite game-hammer-beta game-pencil-engine gamebryo gamecake gamecore-3d gameguru gamekumo gameleon gamemaker gamemaker-studio-2 gameos gameplay gamepower-engine gamesalad 3d-game-studio gamestudio-a8 gamvas-web geex-suite gegameengine gem-1 gem-2 gem-25-halo-mod gem-3 gemix genesis-game-engine genesis3d genie-engine genome geo-mod-2 gewiz-es ggamee-engine ggez gibbo2d gideros glbasic glest-engine glow glue-engine godfather godot-engine goldsource grtech1 grace grace-2 greed-tech-mit greeg-engine greensrc grey-source grime gsc-rts haafs-game-engine hailstorm halo-engine hard-truck-series-engine harfang-3d hat haxeflixel haxepunk hedgehog-engine hell-engine hercules heroengine hex-engine hiber houdini hpl hpl2 hpl3 html5 hypatia-engine i-novae-engine ice-2d-game-engine id-tech-2 id-tech-3 id-tech-4 id-tech-5 id-tech-6 ignite immortal-engine imod-touch impact-js imperial-game-engine-25 imperial-game-engine-2-the-black-throne imperial-game-engine-31 imperium-engine impossible-creatures-engine impulse-engine infernal-engine infinity-engine infinityengine inovator2d1 insanity instead intersect-engine ioquake3 iriszoom iron-engine irrlicht-3d-engine irrlicht-engine isdge itorque2d iw-engine j4game jade jenesis-engine jgame jmonkeyengine k2 kapow-systems-3d kata-engine na276 kinetica kinjin kirikiri2 kivy kiwi-js klik-play-engine kochol-game-engine kokusai-fighting-engine kraken-engine kurok-sdk lacuna-engine lambdahack lance leadwerks-engine leaf-engine lengine libgdx lightfall lightweight-java-game-library limetexte limon-engine liquid lira-sdk-2016 lithtech litiengine love ls3d lua-player lugdunon1 lumberyard lumix-engine lunar-development-kit lux-engine lyn mugen m484-game-creation-system madness maker3d mandate-engine maratisdel maratis marv-engine masstech medusa megaglest-engine meh-engine melonjs mercury mercury-engine methyl mirage-legacy-2d-orpg-engine moai night-source mojito moltengl monkey monogame motion-engine-2 multimedia-fusion multiverse-engine naos ncine ndemic-engine nemesis-engine neoaxis-3d-engine ness-engine newgrounds-3d ngunix nitrous node-webkit no-nonsense notsogoodengine novalis novashell-game-creation-system novelty nuclear-engine nyx-engine o3de obelisk odyssey oengine official-hamster-republic-rpg-creation-engine ogier ogre-engine ogs oldschool-library oni-engine open-game-engine opengine openmw openspace3d orx outerra outerra-engine ouzel owengine panda3d paradigm-engine paradox paradox-2 pathengine pathway2d peak-one-engine pentah perfect-dark-engine pfr-game-engine phaser phoenix-engine phoenix-engine-relic-entertainment phoenix3d photon-cloud phyreengine pi-engine pineapple pipengine pipengine-2d platform-games-editor platinum-arts-sandbox-free-3d-game-maker play-street-engine playcanvas playir polygon-engine popcap-games-framework power-3d-engine-1x project-anarchy project-angels proland prospekt-source proxy-engine pt2-engines pyrogenesis qae-framework qfusion qsm quad-engine quadrion-engine quake-engine quasar quel-solaar quest3d quine-engine r-cube-engine r13bge-r13b-game-engine rage raycasting-game-maker raylib rayne rc-basic rcce2 real-virtuality real-virtuality-2 real-virtuality-3 real-virtuality-4 reality-factory realm-crafter redkit redsky-engine refractor refractor-2 renpy renderware retox retribution retroquad rfs2-engine rigidlight-tech rng-roguelike-sdk rockhard-engine root root-framework rosalila-shooter-engine rpginabox rpg-maker-2003 rpg-maker-mv rpg-maker-mz rpg-maker-vx rpg-maker-vx-ace rpg-maker-xp rpgboss run3-game-engine ryzom-core s-ogl s2engine-hd s3d-engine sage-strategy-action-game-engine samone scape schmetterling scummvm sebbels-mmorpg-bastler serious-engine sfml shatter shiva3d-19 shmup-creator shoot-em-up-kit silk silver-arc silverlight silvershineengine simmetri simulator-reality simvox sio2-interactive sith-engine sizzler-engine skybolt skyline-game-engine slayer slick-2d-slick-ae slip-frag sludge sly-ngine smile-game-builder smilebasic sommerwind source source-2 space-virtual-world spark spark-sdk sphere-game-engine spiral-engine spooker-framework spring spritekit square-engine-plus squeeze-bomb ss-sdk starflare-engine starling stencyl stingray storm-engine-2-working-title storm3d story-game-creator stratagus sugarbombengine super-smash-flash-2-engine superscroller synapse-engine syntensity tac-sys tadpole-treble tak-runtime techengine telejano tes3mp tesseract-engine the-3d-gamemaker the-chiller-engine the-dawn-engine the-exist explorerengine the-fsengine the-glaze-package the-mana-world the-manchu-cross-engine tilemapkit tilengine tiles-engine tilesense tiny2d titan esenthel-engine titan-engine toi-engine tomb-raider-level-editor topaz torque-2d torque-3d torque-game-engine torque-game-engine-advanced torque-x traktor treyarch-ngl tri-engine triodim-engine triplea trivial-engine truevision3d tux twine tyranobuilder ultra-app-kit ut-engine unigine unity unityagk-action-game-kit universal-fighting-engine unknown unreal-development-kit unreal-engine-1 unreal-engine-2 unreal-engine-3 unreal-engine-4 unreal-engine-5 upbge urho3d v-engine v-play valkyrie-engine vassal vcmi vector-based-lines-engine-2d venom-platformer-engine-v30 vereengine vertical-leap vide virtua-form vision-8 visionaire-studio visual-novel-engine visual3d-game-engine vital-engine-3 vixle void-engine volatile-engine vorb voxel-space-2 voxeliq voxel-rage-engine vrender vsgfx vulkan4d wade-game-engine war-zombie-mmo water-bubble wave-engine westwood-2d white-rabbit-engine wicked-engine wimi5 wintermute wolf-rpg-editor wolf3d-engine worldaxis-3d worldforge-project wurfelengine x-framework2 x-ray-engine xash3d-engine xash3d-fwgs-engine xcylin-engine xemplar-2d-game-engine-ae xenko xeno3d-20 xenon-core xero-engine xi-cast-engine xl-engine xna xngine xni xoreos xors3d xtremeworlds1 yeyhay-logic-engine yeyhay-platform-engine yin ymir zamn-engine zdoom zengin zero-engine zerofps zgameeditor zillex-games zodiac-engine zweide zzt-oop"; // result will be an iterator over tuples containing the start and end indices for each match in the string let result = regex.captures_iter(string); for mat in result { println!("{:?}", mat); } }

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 Rust, please visit: https://docs.rs/regex/latest/regex/