highlight.js

    #! shebang
    #! no-shebang

    /* comment */

    function fun()
    {
        var boo = { 'key': [ 1, 2.0, 3.0e1, 004, 0x5 ] };
    }

    class MyClass; // reserved keywords

    // Member objects: text after "."
    object.property instanceof Number;
    iden1.iden2  . iden3.class class;

    var escapes = "aa\b\n\0a\"a\x12a\32a\u{123}a\$\%\ \#\y\aaa\
    aaa";
    var octal = 0o124;
    var bin = 0b1010;

    日本語().ლಠ益ಠლ.ñá = 42;
    δ /No-Regex/

    // Only highlight valid regular expressions, of a single line, after strings
    // See: https://github.com/microsoft/TypeScript-TmLanguage/issues/786
    "text" /No-Regex
    "text" /Regex[:)]*/;
    const a = "6" / 2; /*comment*/ const b = 5;
    console.log("4" / "2"); // 2
    // Single quote
    const a = '6' / 2; /*comment*/ const b = 5;
    console.log('4' / '2'); // 2
    // Template
    const a = `6` / 2; /*comment*/ const b = 5;
    console.log(`4` / `2`); // 2

    // Built-in
    const os = require('os');
    JSON.stringify("hello");
    console.error("hello");
    Math.LOG10E;
    Number.MAX_SAFE_INTEGER;
    String.raw`raw text \.\n${}`

    // Tagged template literals
    tagFunc`
        Hello world!
        ${ alert("Hello!"); }`;
    obj.something.tagFunc`Setting ${setting} is ${value + 5}!`;

    /*
       NOTE: The words "todo", "fixme" and "note" should be rendered in a different style
       within comments, match should be caseless (to test for regexp insensitive attribute).
       The regex used for this rule is */
       String = /\b(?:fixme|todo|note)\b/
       /* Thus,  for example "Notebook" is not caught by
       this rule. (the "?:" in the subpattern is there to avoid the regex engine wasting time
       saving a backref, which is not used for anything. I do not know if the overhead of parsing
       that is greater than the time saved by not capturing the text...)
       The rule for catching these words is placed in a context "Comment common", which is used
       by both comment contexts (single line, multiline) using the new "IncludeRules" item.
    */

    // test if regex support works - nice with new fallthrough prop in context:)
    somestring.replace( /dooh/ , "bah!");
    re=/foo/ig; // hehe

    somestring.search(
           /^foo\w+\s\d{0,15}$/
                      );

            re =
            /dooh/;

    // This is supposedly legal:
    re = somebool ? /foo/ : /bar/;

    // NOTE - Special case: an empty regex, not a comment.
    // The rule uses a positive lookahead assertion to catch it: "//(?=;)".
    re = //;
    re = /a|b/;

    /*
       Tests for the regex parser.
       It will parse classes, quanitfiers, special characters and regex operaters,
       as specified in the netscape documentation for javascript.
       Regexps are only parsed in their clean form, as the RegExp(string) constructor
       is using a quoted string.
       TODO: Find out if more regex feats should be supported.
             Consider using more itemDatas - assertion, quantifier are options.
    */

    re = /^text\s+\d+\s*$/;
    re = /a pattern with caret \(^\) in it/;
    re = /(\d{0,4})\D/;
    re = /[a-zA-Z_]+/;
    re = /[^\d^]+/;
    re = /\s+?\w+\.$/;
    re = /\/\//;
    re = /a|b/;

    // the following are not regexps in E4X (=xml embedded into JavaScript)
    var p = <p>Hello World</p>
    var p = /</
    var p = />/

    // a test if #pop back from a comment will work
    re = /*/foo/*/ /bar/;
    //           ^ POP
    //             ^ we got back after pop in comment, if there is regexp attribs here :-)

    /*
       Some tests if the fallthrough works.
       The fallthrough happens if a regexp is not found in a possible (!) position,
       which is after "search(" or "replace(" or "=" or "?" or ":" in version 0.1 of the xml file
    */

    var foo = 'bar';
    //        ^ fallthrough!

    somestring.replace( new RegExp("\\b\\w+\\b"), "word: $1");
    //                  ^ fallthrough expected. ("new" whould be bold)

    something.method =
        function ( a, b, c ) { /* ... */ }
    //  ^ fallthrough ?!

    something.other =
    function ( d, e, f ) { /* ... */ }
    // fallthrough expected at col 0 ("function" should be bold)

    var ary = new Array(5);
    //        ^ fallthrough ? (if keyword is correctly rendered)

    var b = a ? 1 : 0;
    //          ^   ^ fallthroughs. numbers must be rendered correctly.

    var c = d ? true : false;

    var conditinalstring = b ?
      "something" :
      "something else";
    // guess...

    /*
       Normal program flow...
    */

    if (something)
      dostuff();
    else
      dont();

      return;

    try { bla() } catch (e) { alert("ERROR! : " + e) }

    for (int i=0; i < j; i++)
      document.write("i is" + i + "<br>");

    while (something)
    {
      block();
      picky:
        if (!1)
          break;
        else
          continue;
    }

    with (a) {
      do {
        stuff( b ); // a.b if it exists
      } while (itmakessense);
    }

    switch (i) {
      case 0:
      f();
      break;
      default:
      break;
    }

    // Numerics
    var a = 0xA;
    var b = 0b1;
    var c = 0o7;
    var d = 1.1E+3;
    var e = 1.E+3;
    var f = .1E+3;
    var g = 1E+3;
    var h = 1.1;
    var i = 1.;
    var j = .1;
    var k =  1;
    // Bigint
    const binBig = 0b101n;
    const octBig = 0o567n;
    const hexBig = 0xC0Bn;
    const decBig = 123n;
    // Invalid numbers
    var l = 0xA1t;
    var m = 0b0123;
    var n = 0o29;