自己动手实现jQuery Callbacks完整功能代码详解(2)

// add a function
            this.add = function ( fn )
            {
                if ( typeof fn === 'function' )
                {
                    if ( ops.unique )
                    {
                        // check whether it had been added before
                        if ( fn.name !== '' && hasName( fn.name ) )
                        {
                            return this;
                        }
                    }

ar.push( fn );

if ( ops.memory )
                    {
                        // after added , call it immediately
                        fn.call( this, lastArgs );
                    }
                }

return this;
            };

// remove a function
            this.remove = function ( fn )
            {
                if ( typeof ( fn ) === 'function'
                    && fn.name !== ''
                    && ar.length > 0 )
                {
                    for ( var i = 0; i < ar.length; i++ )
                    {
                        if ( ar[i].name === fn.name )
                        {
                            ar.splice( i, 1 );
                        }
                    }
                }

return this;
            };

// remove all functions
            this.empty = function ()
            {
                ar.length = 0;
                return this;
            };

// check whether it includes a specific function
            this.has = function ( fn )
            {
                var f = false;