Instance Variables in Ruby

Instance variables begin with an at sign () and can be referenced only within class methods. They differ from local variables in that they dont exist within any particular scope. Instead, a similar variable table is stored for each instance of a class. Instance variables live within a class instance, so as long as that instance stays alive, so will the instance variables. Instance variables can be referenced in any method of that class. All methods of a class use the same instance variable table, as opposed to local variables where each method will have a different variable table. It is possible to access instance variables without first defining them, however. This will not raise an exception, but the variables value will be nil and a warning will be issued if youve run Ruby with the -w switch. This example demonstrates the use of instance variables. Note that the shebang contains the -w switch, which will print warnings should they occur. Also, note the incorrect usage outside of a method in the class scope. This is incorrect and discussed below. Why is the test variable incorrect? This has to do with scope and how Ruby implements things. Within a method, the instance variable scope refers to the particular instance of that class. However, in the class scope (inside the class, but outside of any methods), the scope is the class instance scope. Ruby implements the class hierarchy by instantiating Class objects, so there is a second instance at play here. The first instance is an instance of the Class class, and this is where test will go. The second instance is the instantiation of TestClass, and this is where value will go. This gets a bit confusing, but just remember to never use instance_variables outside of methods. If you need class-wide storage, use class_variables, which can be used anywhere in the class scope (inside or outside of methods) and will behave the same. Accessors You normally cannot access instance variables from outside of an object. For instance, in the above example, you cannot simply call t.value or t.value to access the instance variable value. This would break the rules of encapsulation. This also applies to instances of child classes, they cannot access instance variables belonging to the parent class even though theyre technically the same type. So, in order to provide access to instance variables, accessor methods must be declared. The following example demonstrates how accessor methods can be written. However, note that Ruby provides a shortcut and that this example only exists to show you how the accessor methods work. Its generally not common to see accessor methods written in this way unless some sort of additional logic is needed for the accessor. The shortcuts make things a bit easier and more compact. There are three of these helper methods. They must be run in the class scope (inside the class but outside of any methods), and will dynamically define methods much like the methods defined in the above example. Theres no magic going on here, and they look like language keywords, but they really are just dynamically defining methods. Also, these accessors typically go at the top of the class. That gives the reader an instant overview of which member variables will be available outside the class or to child classes. There are three of these accessor methods. They each take a list of symbols describing the instance variables to be accessed. attr_reader - Define reader methods, such as the name method in the above example.attr_writer - Define writer methods such as the age method in the above example.attr_accessor - Define both reader and writer methods. When to use Instance Variables Now that you know what instance variables are, when do you use them? Instance variables should be used when they represent the state of the object. A students name and age, their grades, etc. They shouldnt be used for temporary storage, thats what local variables are for. However, they could possibly be used for temporary storage between method calls for multi-stage computations. However if youre doing this, you may want to rethink your method composition and make these variables into method parameters instead.

Ted Hughes The Shadow of Sylvia Plath Essay example

As England’s Poet Laureate, and recipient of both the Queen’s Gold Medal for Poetry and T.S. Eliot’s prize for poetry, Ted Hughes was an acclaimed poet. The shadow of Hughes late wife, Sylvia Plath, kept Hughes stagnant in his career, in which he was known as â€Å"Her Husband† (Middlebrook). Hughes most recent collection of poems, Birthday Letters, took him over twenty-five years to write, and contains poems which recount the marriage of the couple. Hughes wrote the poems as a loving gesture towards Sylvia, but the poems were misinterpreted as â€Å"an attempt to adjust the public record in the wake of her confession and the mass of commentary which has grown up around them† (Spurr 3). Hughes incorporated into his poetry the ideals of†¦show more content†¦After the affair Plath grew increasingly depressed and eventually committed suicide. He said that â€Å"Plaths death was inevitable, she had been on that track most of her life,† but he could not contend with the additional suicide of Wevill in 1969, which he said was â€Å"utterly within her power, and it was an outcome of her reaction to Sylvia’s action,† which led to Wevill’s suicide.† These past horrific experiences strongly affected Hughes future relationships and poetry. Hughes withdrew into seclusion following the suicides of his lovers. He â€Å"was an intensely private man in an era when privacy is not much allowed† (Wagner 17). He stayed out of the spotlight, because, at the time, feminists accused Hughes of causing the suicide of Plath and Wevill. Even before these events occurred, Hughes viewed the world as: †¦a battlefield. His is the world-view of a betrayed Fundamentalist, who, discovering that God has no care for mans fate, understands the universe to be governed not by divine love but by power. In Hughess earlier books, Nature appeared as a field of violent struggle where only the fittest survived. (Ho ffman 6) His father died in World War I, which led to his doubt of religion and his passion for writing about nature. Throughout his life, Hughes felt that the world was a difficult place to live in and after his lovers died, he refuted this idea.Show MoreRelatedPeople s Love At First Sight By Sylvia Plath1567 Words   |  7 Pages People dream of falling in love at first sight. Sylvia Plath, an American writer, experienced the desirable moment the first time she saw Ted Hughes, an English poet (Middlebrook). The romantic relationship between Ted Hughes and Sylvia Plath grew instantly. They both shared a love of writing, but yet their relationship began to go downhill five years after their marriage (Popova). The marriage between Ted Hughes and Sylvia Plath was destructive because of Sylvia’s unstable mental health and Ted’sRead MoreContributions Of Sylvia Plath1302 Words   |  6 Pagesand development of literature. Sylvia Plath was also a profound writer and one of the most respected poets and prose writer of her time as well. She was once described as â€Å"one of the most celebrated and controversial of postwar poets writing in English† (â€Å"Sylvia Plath†). Many of her poems talked about her own mental issues, her marriage problems, conflicts with her parents that were left unresolved, or her vision of herself. Before her death at the age of thirty, Plath had a multitude of followersRead MoreSylvia Plath was American short-story writer, poet and novelist that was born on October 27, 1932900 Words   |  4 PagesSylvia Plath was American short-story writer, poet and novelist that was born on October 27, 1932 in Boston, Massachusetts and died on February 11, 1963. Sylvia Plath is best known for, her books of poems, â€Å"The Colossus and Other Poems Collection† and the â€Å"Ariel Collection† of Poems.Plath’s poetry was known for its rhyme, alliteration and disturbing and violent imagery. Plath’s poetry is c onsidered part of the Confessional movement, which became very popular in the United States during the 1950sRead Morequot;Sylvia Plath- Feminine Side of the Feminist Iconquot; Essay1576 Words   |  7 Pages Sylvia Plath was a typical example of her generation, inpatient and greedy for life but this description has a bit different meaning. Plath indeed desired artistic fulfilment but she wanted to be an ideal wife and mother at the same time. When Ted Hughes published his first poetry volume The Hawk in the Rain she was very happy that she will follow his footsteps. Throughout their marriage she was in the shadow of her husband and we can argue whether it was her conscious choice and to whatRead MoreHow Sylvia Plaths Life is Reflected in the Poems Daddy, Morning Song, and Lady Lazarus2237 Words   |  9 PagesHow Sylvia Plaths Life is Reflected in the Poems Daddy, Morning Song, and Lady Lazarus Sylvia Plath has had an exciting life, if I can use this word. Her father died from an undiagnosed diabetes when she was eight. At the same time, a short couplet that she wrote was published in the Boston Sunday Herald. Later, she won scholarships to study in Smith, Harvard, and finally Cambridge. There, Plath married Ted Hughes, who was a good poet, too. What amazes me in her lifeRead MoreSylvia Plath s Life And Accomplishments892 Words   |  4 PagesSylvia Plath was born in Jamaica Plain, Massachusetts on October 27, 1932. Plath’s family moved to Winthrop, Massachusetts when she was four years old. When she was eight, her father, Otto Plath died, this was same year she published her first poem. Plath was a very hardworking, persistent student in high school. She was soon rewarded after her graduation with many published works and successes. Plath attended Smith College with two scholarships. At Smith, she excelled academically and achieved manyRead MoreWriting Styles of Sylvia Plath Essay1277 Words   |  6 PagesThe Life and Writings of Sylvia Plath After reading and discussing many poets and their written work, I have realized that not only pain, but any emotion that the poet is feeling, plays a large part in how the poems express themselves through their writing. I have chosen to explore Sylvia Plath and the poems she has written and how her pain and personal experiences have influenced her poetry. Similar to many other authors of the twentieth century, Sylvia Plath’s writing was influenced largelyRead MoreDeath Represenataion in Sylvia Plaths Selected Poems2941 Words   |  12 PagesDeath Representation in Sylvia Plaths Selected Poems Mohamed Fleih Hassan Instructor English Dept./ Abstract Death is one of the significant and recurrent themes in the poetry of Sylvia Plath. This paper aims at showing the poets attitudes towards death. Certain poems are selected to show the poets different attitudes to death: death as a rebirth or renewal, and death as an end. Most obvious factors shaped her attitudes towards death were the early death of her father that left her unsecuredRead MoreEssay On Sylvia Plath1607 Words   |  7 Pageshas to offer. Sylvia Plath was a confessional poet, using her personal experiences and very real situations to give â€Å"negative† emotions the artistic charm and characteristics traditionally saved for â€Å"positive† emotions. Her father died in her eighth year of life, and although this event tormented her until her own death, time went on. She married Ted Hughes, the two of them encouraging each other’s careers as much as they could, but still there was tension between them. It was when Plath learnt of herRead More`` Let Me Live, Love, And Say It Well Good Sentences `` Good Sentence ``2052 Words   |  9 Pagesâ€Å"Let me live, love, and say it well in good sentences† (Plath). Sylvia Plath is a confessional poet who is often the subject of her poetry. Throughout the majority of her life Sylvia Plath simply wished to live an ordinary life. However, Plath endured many tragedies during her life that influenced her stylistic approach to poetry; often based off her emotions. In her poems, Plath acquires her central source of influence from her personal life and employs a variety of techniques to brand her message

Wfnx Best Music Poll Concert free essay sample

So there we were, within a mass of leather jackets, heavy black eyeliner, and psychedelic tent dresses, in line to be searched before the WFNX Best Music Poll Concert, on April 17. The bill contained Jesus Jones, Happy Mondays, SoHo, and Iggy Pop. We had fled from our boarding school to spend a single evening somewhere where the most popular dance song wasnt by Vanilla Ice or New Kids on the Block. In our hands were two blue and white tickets ominously labelled Obstructed View. You can imagine our surprise when, instead of seats in the back, behind a pillar, we were led to the front row absolute corner, and seated. What obstructed our views, you ask? The colossal stack of super power speakers, I tell you! We could almost see half the stage when we leaned, but boy we could hear EVERYTHING! SoHo went on first, after much too much ado from Troy or Ti, or one of the T deejays from FNX. We will write a custom essay sample on Wfnx Best Music Poll Concert or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page I can honestly say that I was impressed by the band. Though I recognized only Hippy Chick, their melodies stuck in my head, and their vocals were admirable. By the way, they too wore psychedelic tent dresses, the attire of the evening. One downfall of the concert was that, in the ever-too-long gaps between performers, the nameless T deejay conducted a really de-pressing awards ceremony. Al-though some of the acceptance speeches were entertaining, I am glad to say that my obstructed view seat saved me from the horror of watching the whole ordeal. Even the T deejay knew who would steal the show that night. Before he introduced Jesus Jones, he called them THE band that will ROCK this house tonight. Jesus Jones blew me away. Their sound was good, their songs unforgettable, their stage manner really encouraging to the audience. At one point, the singer asked that the house lights be turned on so everyone could see each other, saying Were not the only performers here. The highlight of their set for me was Welcome Back Victoria. Im glad they had the guts to turn all the guitars way down, and let their singer make everyone listen. Another great thing were the two strobe lights perched on both sides of the stage during Jesus Jones performance. I prefer this system to any of the fancy light shows other bands put on. I loved watching the bands various bodies and long hair convulse between the pulsing lights. After another long break, Iggy Pop performed. He did a short set, but the gist of his performance was taking his clothes off. When he got down to his gray jockeys, I was almost embarrassed for the poor man. What a skinny, wrinkled body! I was not impressed by his performance, but his guitarist shows promise for a real heavy metal axemaster. The final act of the night were the Happy Mondays. They had a fancy psychedelic light system, but in all its splendor I still liked Jesus Jones for their strobe lights. Happy Mondays made good music, just like their album, but one would have been just as well off to sit home and listen to the album, because the singer sat on the drum podium, back to the audience, and the rest of the band did basically the same. Also, they dressed their overweight backup singer like an S M goddess, complete with whip, which I thought was repulsive and sexist. Such is the world of music, I suppose. So thats it. Overview: Jesus Jones incredible; SoHo pretty darn good; Happy Mondays good music, kinda boring; Iggy Pop please keep your clothes on. Thanks for reading, happy concert-going to you, too. n

The Persian Gulf War Essays (1900 words) - , Term Papers

The Persian Gulf War On August 2nd, 1990 Iraqi military forces invaded and occupied the small Arab state of Kuwait. The order was given by Iraqi dictatorial president Saddam Hussein. His aim was apparently to take control Kuwait's oil reserves (despite its small size Kuwait is a huge oil producer; it has about 10 per cent of the world's oil reserves ). Iraq accused Kuwait, and also the United Arab Emirates, of breaking agreements that limit oil production in the Middle East. According to Saddam Hussein, this brought down world oil prices severely and caused financial loss of billions of dollars in Iraq's annual revenue. Saddam Hussein had the nearly hopeless task of justifying the invasion. He plead the fact that Kuwait had been part of the Ottoman province of Basra, a city in the south of Iraq. However, the Ottoman province collapsed after World War I and today's Iraqi borders were not created until then. There was also a further and more obvious blunder in a bid to justify this illegal invasion. Baghdad, the capital of Iraq, had namely recognized Kuwaiti independence in 1963. Furthermore, Hussein claimed that Kuwait had illegally pumped oil from the Iraqi oil field of Rumaila and otherwise conspired to reduce Iraq's essential oil income. By invading Kuwait, Iraq succeeded in surprising the entire world. The USA ended her policy of accommodating Saddam Hussein, which had existed since the Iran-Iraq war. Negative attitude toward Iraq was soon a worldwide phenomenon. The United Nations Security Council passed 12 resolutions condemning the invasion. The ultimate decision was to use military force if Iraq did not withdraw unconditionally by January 15, 1991. Then, when the deadline was set, it was time to start preparing for the worst-the war. President George Bush confronted little difficulty in winning Americans' support for the potential war against Iraq. However, the government found it difficult to decide upon and state one overriding reason for going to war. Was it to oppose aggression or was it just to protect global oil supplies? Other powers were more directly concerned as consumers of Persian Gulf oil, but they were not as eager to commit military force, to risk their youth in battle and to pay for the costs of the war. Critics of President Bush continued to maintain that he was taking advantage of the issue of energy supplies in order to manipulate the U. S. public opinion in favor of war. After consulting with U. S. Secretary of Defense Dick Cheney in early August 1990, King Fahd of Saudi Arabia invited American troops onto Saudi soil. He had seen Kuwait's destiny; therefore, he wanted protection. It was also the interest of the USA to stop any further advantage of the Iraqi army. The deployment was called ?Operation Desert Shield.? These troops were armed with light, defensive weaponry. On November 8, 1990 President Bush announced a military buildup to provide an offensive option, ?Operation Desert Storm,? to force Iraq out of Kuwait. The preparation of the operation took two and a half months and it involved a massive air- and sea lift. Finally, in January 1991, the U. S. Congress voted to support Security Council resolution 660. It authorized using ?all necessary means? if Iraq did not withdraw from Kuwait by January 15. Shrugging off this final warning, Saddam Hussein resolutely maintained the occupation of Kuwait. The United States established a broad-based international coalition to confront Iraq militarily and diplomatically. The military coalition consisted of Afghaniez, Argentina, Australia, Bahrain, Bangladesh, Belgium, Canada, Czechoslovakia, Denmark, Egypt, France, Germany, Greece, Hungary, Honduras, Italy, Kuwait, Morocco, the Netherlands, New Zealand, Niger, Norway, Oman, Pakiez, Poland, Portugal, Qatar, Saudi Arabia, Senegal, South Korea, Spain, Syria, Turkey, the United Arab Emirates, the United Kingdom, and the United States. The war also was financed by countries which were unable to send in troops. Saudi Arabia and Kuwait were the main donors. More than $53 billion was pledged and received. Before the war, it appeared obvious that Iraq would have very little chance against the Coalition. The relative strength between the parties was extremely unequal. The most critical difference was that the Coalition had a total of 2600 aircraft, over three times more than Iraq's 800 aircraft. Most Arab observers thought Hussein would