is it JavaScript? its upto you to call or apply

Happen to see this nice cool JavaScript code somewhere in web.

// 
function is(it) { 
   alert(this+" is " +it);
}
is("global");  // [object Window] is global
is.call(5,"number");  // 5 is number
is.apply("A", ['string']);  // A is string
alert.is=is;  
alert.is("function");  // function alert() { [native code] } is function
// 

is it JavaScript? its upto you to call or apply.

Hope JavaScript folks enjoy this.

Restricting textarea maxlength using JavaScript

Here is the cross browser javascript code to fix the maxlength property of textarea

Basic html structure
<!-- html structure used -->
<textarea id="remarks" name="remarks" maxlength="20" rows="5" cols="50"></textarea>
<div class="charLeft">characters left:20</div>
<!-- -->

CSS used
/* css used */
.​charLeft​ {color:#ccc;}​
/*  */

// Javascript code used
var restrictCharacters = (function(){

    $(function(){
        $("#remarks").bind("keydown keyup", function(e){
            restrictCharacters.checkRemarksLength($("#remarks"),e);
        });
    });

    return {
        remarks:"",
        checkRemarksLength: function(field,e){
            var curLength = field.val().length,
                maxLength = parseInt(field.attr('maxlength')),
                iam = field.attr('name');
            if(e.type == 'keydown'){
                if(curLength > maxLength) return false;
                else this.remarks= field.val();
            }
            if(e.type == 'keyup') {
                if(maxLength - curLength >= 0) $('.charLeft').html('Charecters left: '+(maxLength-curLength));
                else field.val(this.remarks);
            }
        }
    }
})();
// 

Want to play around??
				

this is new bad in JavaScript

this is powerful but at the same time if used without care it is dangerous too. Consider the example snippet below

// define Human class
var Human = function(name) {
    this.name = name;
    this.say = function(){
        return "I am " + this.name;
    };
};
var author = new Human('raja');
var badAuthor = Human('ford');  // new keyword missing

alert(typeof author); // object
alert(typeof badAuthor); // undefined because context changed to window
alert(author.name)  // raja
alert(window.name)  // ford

Notice how missing new keyword changing the context to window object.

Play with it.