js 闭包

function createFunctions(){
                var result = new Array();
                
                for (var i=0; i < 10; i++){
                    result[i] = function(){
                        return i;
                    };
                }
                
                return result;
            }

var funcs = createFunctions();
            
            //every function outputs 10
            for (var i=0; i < funcs.length; i++){
                document.write(funcs[i]() + "<br />");
            }