Regular Expressions 101

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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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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

/
/

Test String

Code Generator

Generated Code

const regex = /^[\s\S]{0,30}/; // Alternative syntax using RegExp constructor // const regex = new RegExp('^[\\s\\S]{0,30}', '') const str = `</head> <body> <div id="kJAQ_" class="z-temp"><div id="zk_proc" class="z-loading"><div class="z-loading-indicator"><span class="z-loading-icon"></span>Processing...</div></div></div> <script class="z-runonce" type="text/javascript"> zkmx( [0,'kJAQ_',{dt:'z_oec',cu:'/EfectoresWeb',uu:'/EfectoresWeb/zkau',ru:'/login.isp'},[ ['zul.utl.Style','zk_comp_1',{visible:false,src:'/EfectoresWeb/css/PamiStyle.css'},[]], ['zul.wgt.Div','zk_comp_2',{id:'div',style:'width:90%;margin:0 auto 0 auto;align:center',prolog:'\\n\\t'},[ ['zul.wgt.Include','zk_comp_3',{prolog:'\\n\\t\\t',_xcnt:'<div id="kJAQ0" class="z-temp"><div id="zk_proc" class="z-loading"><div class="z-loading-indicator"><span class="z-loading-icon"></span>Processing...</div></div></div>',_childjs:function(){zkmx( [0,'kJAQ0',{ow:'zk_comp_3'},[ ['zul.wnd.Window','zk_comp_38',{id:'winHeader',\$\$onSize:false,\$\$onMaximize:false,\$\$onOpen:false,\$\$onMinimize:false,\$\$onZIndex:false,\$onClose:true,\$\$onMove:false,prolog:'\\n\\t'},[ ['zul.box.Box','zk_comp_39',{},[ ['zul.box.Box','zk_comp_40',{id:'hbox_header',align:'end'},[ ['zul.wgt.Image','zk_comp_41',{src:'/EfectoresWeb/img/top.jpg'},[]]],'horizontal']],'vertical']]]]]); }},[]], ['zul.wnd.Window','zk_comp_4',{id:'winLogin',\$onOK:true,\$onClose:true,prolog:'\\n\\t \\t'},[ ['zul.box.Box','zk_comp_5',{},[ ['zul.box.Box','zk_comp_6',{id:'hbox_menu'},[],'horizontal'], ['zul.wgt.Groupbox','zk_comp_7',{\$\$onOpen:false,width:'890px',closable:false},[ ['zul.wgt.Caption','zk_comp_8',{id:'caption_login',sclass:'z-title',label:'Login'},[]], ['zul.grid.Grid','zk_comp_9',{\$\$onRender:true,\$`; let m; if ((m = regex.exec(str)) !== null) { // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions