zepto判断左右滑动

    var startPosition, endPosition, deltaX, deltaY, moveLength;
            $(".content").bind(‘touchstart‘, function(e){
                var touch = e.touches[0];
                startPosition = {
                    x: touch.pageX,
                    y: touch.pageY
                }
            }) .bind(‘touchmove‘, function(e){
                var touch = e.touches[0];
                endPosition = {
                    x: touch.pageX,
                    y: touch.pageY
                };  

                deltaX = endPosition.x - startPosition.x;
                deltaY = endPosition.y - startPosition.y;
                moveLength = Math.sqrt(Math.pow(Math.abs(deltaX), 2) + Math.pow(Math.abs(deltaY), 2));
            }).bind(‘touchend‘, function(e){
                if(deltaX < 0) { // 向左划动
                    console.log("向左划动");
                } else if (deltaX > 0) { // 向右划动
                    console.log("向右划动");
                }
            });