createXhr

var o = {
        createXhr : function(){
            try {
                console.log("xx");
                return new XMLHttpRequest();
            }catch(e){}
            try{
                return new ActiveXObject("Microsoft.XMLHTTP");
            }catch(e){}
        }
    };
    o.createXhr();// xx
    o.createXhr();// xx
    o.createXhr();// xx

var O = {
        createXhr : (function(){
            try {
                console.log("yy");
                return new XMLHttpRequest();
            }catch(e){}
            try{
                return new ActiveXObject("Microsoft.XMLHTTP");
            }catch(e){}
        })(),

        name : "NIck"
    };
    O.createXhr;
    O.createXhr;
    O.createXhr;

    var p = {
        createXhr : (function(){
            var f;
            if(window.XMLHttpRequest){
                f = new XMLHttpRequest();
            }else{
                f = new ActiveXObject("Microsoft.XMLHTTP");
            }
            return f;
        })()
    };

    console.log(p.createXhr);// XMLHttpRequest