自己动手实现jQuery Callbacks完整功能代码详解(7)

// 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;

if ( typeof ( fn ) === 'function'
                        && fn.name !== ''
                        && ar.length > 0 )
                    {
                        for ( var i = 0; i < ar.length; i++ )
                        {
                            if ( ar[i].name === fn.name )
                            {
                                f = true;
                                break;
                            }
                        }
                    }

return f;
                };