Identifiers & IdentiferNames

    //Identifiers and IdentifierNames in JavaScript
    {
      /*************
       * //Reserved keywords
       * break, case, catch, class, const, continue, debugger, default, delete, do, else,
       * export, extends, finally, for, function, if, import, in, instanceof, new, return,
       * super, switch, this, throw, try, typeof, var, void, while, with, yield,
       * enum, true, false, null,
       *
       * //In strict mode
       * implements, interface, let, package, private, protected, public, static
       *
       * //In modules
       * await
       *
       * //In older versions of ECMAScript
       * abstract, boolean, byte, char, double, final, float, goto, int, long, native,
       * short, synchronized, throws, transient, volatile
       */
    }
    
    var $;
    let _;
    let aas;
    let abc1;
    let $as3423d_;
    let abc123_ = 'something';
    const STEVE = Symbol();
    
    let obj = {
      $: 'a',
      _: 'b',
      abc: 'c',
      [abc123_]: 'd',
      [STEVE]: 'e',
      1: 'f',
      '1.213423': 'g',
    };