防抖节流函数
function _debounce(fn, delay) { var delay = delay || 200; var timer; return function() { var th = this; var args = arguments; if (timer) { clearTimeout(timer); } timer = setTimeout(function() { timer = null; fn.apply(th, args); }, delay); }; } function _throttle(fn, interval) { var last; var timer; var interval = interval || 200; return function() { var th = this; var args = arguments; var now = +new Date(); if (last && now - last < interval) { clearTimeout(timer); timer = setTimeout(function() { last = now; fn.apply(th, args); }, interval); } else { last = now; fn.apply(th, args); } }; }