延迟执行
这是个很有意思的编程思想，如果拿出来做为题目，很多中高级工程师也很难短时间想明白
使用
js
jQuery.fn.delay = function (time, type) {
time = jQuery.fx ? jQuery.fx.speeds[time] || time : time;
type = type || 'fx';
return this.queue(type, function (next, hooks) {
var timeout = window.setTimeout(next, time);
hooks.stop = function () {
window.clearTimeout(timeout);
};
});
};当我看到这种用法的时候，我就在想，是不是我想的那个原理，果然读到下面的源码，和我的想法差不多
原理
js
queue: function( elem, type, data ) {
var queue;
if ( elem ) {
type = ( type || "fx" ) + "queue";
queue = dataPriv.get( elem, type );
// Speed up dequeue by getting out quickly if this is just a lookup
if ( data ) {
if ( !queue || Array.isArray( data ) ) {
queue = dataPriv.access( elem, type, jQuery.makeArray( data ) );
} else {
queue.push( data );
}
}
return queue || [];
}
},
dequeue: function( elem, type ) {
type = type || "fx";
var queue = jQuery.queue( elem, type ),
startLength = queue.length,
fn = queue.shift(),
hooks = jQuery._queueHooks( elem, type ),
next = function() {
jQuery.dequeue( elem, type );
};
// If the fx queue is dequeued, always remove the progress sentinel
if ( fn === "inprogress" ) {
fn = queue.shift();
startLength--;
}
if ( fn ) {
// Add a progress sentinel to prevent the fx queue from being
// automatically dequeued
if ( type === "fx" ) {
queue.unshift( "inprogress" );
}
// Clear up the last queue stop function
delete hooks.stop;
fn.call( elem, next, hooks );
}
if ( !startLength && hooks ) {
hooks.empty.fire();
}
},