Is JavaScript getting worse?(buzzdecafe.github.io)

    >>> def f():
    ...     type(x)
    ...     x = 10
    ...
    >>> f()
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      File "<stdin>", line 2, in f
    UnboundLocalError: local variable 'x' referenced before assignment

    irb(main):010:0> def f()
    irb(main):011:1>     x.class
    irb(main):012:1>     x = 10
    irb(main):013:1> end
    => nil
    irb(main):014:0> f()
    NameError: undefined local variable or method `x' for main:Object
    	from (irb):11:in `f'
    	from (irb):14:in `evaluate'
    	from org/jruby/RubyKernel.java:1101:in `eval'
    	from org/jruby/RubyKernel.java:1501:in `loop'
    	from org/jruby/RubyKernel.java:1264:in `catch'
    	from org/jruby/RubyKernel.java:1264:in `catch'
    	from C:/jruby-1.7.12/bin/jirb_swing:53:in `(root)'

    public class Test {
    	public void f() {
    		boolean isInt = x instanceof Integer;
    		Integer x = 10;
    	}
    }
    >javac Test.java
    Test.java:3: error: cannot find symbol
                    boolean isInt = x instanceof Integer;
                                    ^
      symbol:   variable x
      location: class Test
    1 error

    JSONParseStream.prototype = Object.create(Transform.prototype);
    function JSONParseStream(options) {

    Transform.call(this, options);
        ...
    }
   
    JSONParseStream.prototype = Object.create(Transform.prototype);

    Object.defineProperty(JSONParseStream.prototype, 'constructor', {
        value: JSONParseStream,
        enumerable: false,
        writable: true,
        configurable: true
    }

    JSONParseStream.prototype._transform = function(chunk, encoding, cb) {
        ...
    }

    class JSONParseStream extends Transform {
        constructor(options) {
            super(options);
            ...
        },
        _transform(chunk, encoding, cb) {
            ...
        }
    }