jQuery.Callbacks = function( options ) {// Convert options from String-formatted to Object-formatted if needed// (we check in cache first)options = typeof options === "string" ?( optionsCache[ options ] || createOptions( options ) ) :jQuery.extend( {}, options );

var // Last fire value (for non-forgettable lists)
        memory,// Flag to know if list was already fired
        fired,// Flag to know if list is currently firing
        firing,// First callback to fire (used internally by add and fireWith)
        firingStart,// End of the loop when firing
        firingLength,// Index of currently firing callback (modified by remove if needed)
        firingIndex,// Actual callback listlist = [],// Stack of fire calls for repeatable listsstack = !options.once && [],// Fire callbacksfire = function( data ) {..................},self = {add: function() {..............},remove: function() {................},has: function( fn ) {..................},empty: function() {..................},disable: function() {..................},disabled: function() {................},lock: function() {..............},locked: function() {..............},fireWith: function( context, args ) {...................},fire: function() {................},fired: function() {................}};

disabled: function() {return !list;
},
locked: function() {return !stack;
},
fired: function() {return !!fired;
}

fire: function() {self.fireWith( this, arguments );return this;
},

if ( list[ firingIndex ].apply( data[ 0 ], data[ 1 ] ) === false && options.stopOnFalse ) {

fireWith: function( context, args ) {args = args || [];args = [ context, args.slice ? args.slice() : args ];if ( list && ( !fired || stack ) ) {if ( firing ) {stack.push( args );} else {fire( args );}}return this;
},

fire = function( data ) {memory = options.memory && data;fired = true;firingIndex = firingStart || 0;firingStart = 0;......................

stack = !options.once && [],

firing = true;for ( ; list && firingIndex < firingLength; firingIndex++ ) {if ( list[ firingIndex ].apply( data[ 0 ], data[ 1 ] ) === false && options.stopOnFalse ) {memory = false; // To prevent further calls using addbreak;}}
firing = false;

if ( list ) {if ( stack ) {if ( stack.length ) {fire( stack.shift() );}} else if ( memory ) {list = [];} else {self.disable();}
}

add: function() {if ( list ) {// First, we save the current lengthvar start = list.length;(function add( args ) {jQuery.each( args, function( _, arg ) {var type = jQuery.type( arg );if ( type === "function" ) {if ( !options.unique || !self.has( arg ) ) {list.push( arg );}} else if ( arg && arg.length && type !== "string" ) {// Inspect recursively
                    add( arg );}});})( arguments );// Do we need to add the callbacks to the// current firing batch?if ( firing ) {firingLength = list.length;// With memory, if we're not firing then// we should call right away} else if ( memory ) {firingStart = start;fire( memory );}}return this;
},

fire = function( data ) {memory = options.memory && data;fired = true;firingIndex = firingStart || 0;firingStart = 0;firingLength = list.length;firing = true;for ( ; list && firingIndex < firingLength; firingIndex++ ) {if ( list[ firingIndex ].apply( data[ 0 ], data[ 1 ] ) === false && options.stopOnFalse ) {memory = false; // To prevent further calls using addbreak;}}firing = false;if ( list ) {if ( stack ) {if ( stack.length ) {fire( stack.shift() );}} else if ( memory ) {list = [];} else {self.disable();}}
},

//once
var cb = $.Callbacks('once');
cb.add(function(){alert('a');
});
cb.add(function(){alert('b');
});
cb.fire();//弹出a,b
cb.fire();//不执行//memory
var cb = $.Callbacks('memory');
cb.add(function(){alert('a');
});
cb.add(function(){alert('b');
});
cb.fire();//弹出a,b

cb.add(function(){ //弹出calert('c');
});//once memory
var cb = $.Callbacks('once memory');
cb.add(function(){alert('a');
});
cb.add(function(){alert('b');
});
cb.fire();//弹出a,b

cb.add(function(){ //弹出calert('c');
});
cb.fire(); //不执行//add方法多个参数逗号隔开
var cb = $.Callbacks();
cb.add(function(){alert('a');
},function(){alert('b');
});cb.fire(); //弹出a,b//stopOnFalse
var cb = $.Callbacks('stopOnFalse');
cb.add(function(){alert('a');return false;
},function(){alert('b');
});cb.fire();//弹出a//lock()
var cb = $.Callbacks('memory');
cb.add(function(){alert('a');
});cb.fire();//弹出a
cb.lock();//锁住fire()

cb.add(function(){ //弹出balert('b');
});
cb.fire();//不执行//remove()
var cb = $.Callbacks();
var fn1 = function(){alert('a');
};
var fn2 = function(){alert('b');
};
cb.add(fn1);
cb.add(fn2);
cb.fire(); //弹出a,b

cb.remove(fn1,fn2);
cb.fire();//不执行