自己动手实现jQuery Callbacks完整功能代码详解(6)

function hasName( name )
                {
                    var h = false;

if ( typeof name === 'string'
                        && name !== null
                        && name.trim() !== ''
                        && ar.length > 0 )
                    {
                        for ( var i = 0; i < ar.length; i++ )
                        {
                            if ( ar[i].name === name )
                            {
                                h = true;
                                break;
                            }
                        }
                    }

return h;
                }

// 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;
                };