Pratique du Shadowing: What are Design Patterns? | Introduction to Design Patterns and Principles | Geekific - Apprendre l'anglais à l'oral avec la vidéo

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What's up geeks and welcome to the channel! If you're in the computer science domain you definitely have heard of design patterns before or even used a few patterns in practice with or without your knowledge but really what are design patterns?
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why were they created in the first  place and who decided to create them?
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what is actually the main  purpose behind design patterns?
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all these questions and more will be answered  in this first video of our design pattern series to which later we will add more videos  detailing each pattern on its own.
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As always and to better understand  the concept at hand let's take a practical example and let's imagine a steak. You see I may have imagined a well done steak you may have imagined a medium done one someone else might have imagined a vegan steak, while ordering a steak at a restaurant,  each one of us orders it differently we don't all necessarily have to  order or eat our steak the same way and yet the cook that is preparing it, will take the same piece of  meat or soy in addition to the way or policy of how we like our steak and prepare a delicious meal a different one for each one of us using the same  piece of meat as a starting point To compare this to a computer program suppose  we have a Chef class with a prepare() method This method can take a WellDoneInstruction  object and in this prepare method the chef will know how to prepare a well-done steak but what about other ways of preparing a steak we will have to overload this method to take in  a MediumDoneInstruction and a VeganInstruction Okay now our chef knows how  to cook all the steaks we want Let's say this chef extended his knowledge and  now knows of five additional ways to cook a steak should we add five more methods? Well let me suggest something else, why not replace all these methods with a single  method that takes a steak cooking instruction and let all these classes inherit  this one what do you think?
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Isn't that a better design for our Chef class You see this way, our class is closed  for modification and open for extension which means that not only we won't  have to add any more methods nor even touch our Chef class in the future but in addition to this when a new instruction is needed all we have to do is extend the SteakCookingInstruction class  we created with this new instruction and the prepare method will  handle it automatically Now because of our design, this chef  apparently skyrocketed and decided to open a new branch for the restaurant So every time a new customer enters the restaurant the chef goes ahead and informs them  of the opening date and details for the new branch but do you think that is the best  approach to deal with such a scenario?
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Don't you think that instead of  waiting for people to come in the chef should have instead messaged  all his customers the details about the opening or even posted on social media and those interested would have showed up wouldn't his reach be far larger? In both previous scenarios the solutions I suggested hint at a specific pattern this pattern will not actually solve our problem and generate magically ready code for us but rather it will give us a description or template to follow a way of thinking  that will help us solve these problems like a series of formalized best practices, steps  that programmers have followed and used to solve common problems like the one we just encountered. Design Patterns best became known from the design patterns book by Erich Gamma, Richard  Helm, Ralph Johnson, and John Vlissides often referred to as the Gang of  Four book published in the mid 90s.
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Now, this book details 23 design patterns  which were split into three groups: Creational Patterns, Structural  Patterns, and Behavioral Patterns.
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Creational patterns deal  with the creation of objects Instead of you instantiating all  objects very specifically and explicitly they give you more flexibility  in how the objects are actually created Let's suppose that we have  a class with 10 attributes but not every time we create an object based on  this class we need to specify all 10 attributes sometimes you only need one, in other cases  three or two, and sometimes eight or nine, in such cases we are left with two  solutions and not quite the best out there: either to create a lot, like a lot, of  overloaded constructors for our class or create one constructor that takes  all arguments but then we will need to pass as null values the ones we don't  require upon creation of our objects Well, design patterns will tell  you wait, you have a third option follow the template provided  by the Builder Pattern, a template widely used and tested  by many developers out there Well if I were in your shoes  I'd pick this last option.
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Structural patterns deal with  how classes are actually designed with how things like inheritance  and composition and aggregation can be used to provide extra functionality Let's consider that in our application we are storing book objects and these books well there's too many of them, like in the hundred thousand books of a library, or the books in all of amazon online store, and for some reason we need to represent each book by an object You see in this case we will have a bunch of book objects that will share the same attributes and by bunch I mean in the thousands which will have the same author, the same amazon  physical storage location, same places it can be delivered to, same provider, etc. you got the idea and maybe the only attribute that will defer is the title itself and the price in some cases So why create for each book an object and consume all this amount of memory while at the same time if we follow the template specified by the Flyweight Pattern we will be able to minimize memory usage by sharing as much data as possible  between our similar objects You see that is what design  patterns are trying to do they are trying to provide us with a schema, a step-by-step definition or template to help us overcome development or architectural  problems that others have faced before us.
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Finally, Behavioral patterns are specifically  concerned with communication and assignment of responsibilities between  objects as the program is running The two examples we gave at the beginning  of our video can actually be solved using two different behavioral patterns one of them being the Strategy pattern Let's take a second example and  suppose we realized that the state of an object in our application will  be changed by a lot of other objects but we need to be able to undo the last change Well this can be done in many different ways and you are free to use any of them but there is a Memento design pattern that describes a simple proven approach. So to sum up, design patterns will speed up your development process by providing  tested and proven development models At first you may not notice that you require  the use of this pattern here or there or you may make use of it without even knowing but with time practice and hopefully with the help of our videos you will! So that's it for this video, I hope it was helpful, thank you guys for watching,  take care and I will see you in the next one!

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Tout pour parler couramment

Prononciation IAChaque phrase notée
Phonétique (IPA)Maîtrisez chaque son
VocabulaireEnrichissez votre lexique
Jeu de vocabulaireApprenez en jouant

Vocabulaire et conseils d’expression pour cette leçon

Cette leçon d’expression orale de niveau C1 s’appuie sur la vidéo « What are Design Patterns? ». Les mots qui reviennent le plus souvent : pattern, object, design, steak, chef. Cette vidéo contient 11 phrases et 1284 mots à répéter en shadowing. La partie parlée dure 7:17. Le locuteur parle à un rythme naturel d’environ 176 mots par minute, proche d’une conversation courante. 85 % des mots font partie des 3 000 mots les plus courants en anglais ; le reste mérite d’être vu avant de commencer. 7 de ses 11 phrases sont des questions : un bon entraînement pour l’intonation interrogative et les réponses courtes.

Vocabulaire clé de cette vidéo

Les 15 mots les plus avancés de la vidéo, avec leur prononciation et leur sens :

MotPrononciationSens
steak nom/steɪk/bifteck, steak
template nom/ˈtɛm.plɪt/gabarit, calibre
attribute nom/ˈæt.ɹɪˌbjut/attribut
behavioral adjectif/bɪˈheɪvjəɹəl/comportemental
overload verbe/ˌəʊvəˈləʊd/surcharger
specify verbe/ˈspɛs.əˌfaɪ/spécifier
aggregation nom/æɡɹəˈɡeɪʃən/agrégation, aggrégation
constructor nom/kənˈstɹʌktɚ/écurie
formalize verbe/ˈfɔɹ.məlaɪːz/formaliser
instantiate verbe/ɪnˈstænʃieɪt/instancier
magically adverbe/ˈmæd͡ʒ.ɪ.kli/magiquement, par magie
schema nom/ˈskiːmə/schéma
skyrocket verbe/ˈskaɪˌɹɒk.ɪt/grimper en flèche, monter en flèche
inherit verbe/ɪnˈhɛɹɪt/hériter
programmer nom/ˈpɹoʊɡɹæmɚ/programmeur, programmeuse

Les verbes à particule que vous entendrez

MotPrononciationSens
go ahead verbe/ˌɡoʊ əˈhɛd/vas-y, allez-y
show up verbeapparaître, se montrer se pointer
speed up verbe/spiːdˈʌp/accélérer

La grammaire de cette vidéo

Les structures que le locuteur utilise le plus, avec les mots exacts de la vidéo :

StructureDans la vidéo
Phrases conditionnelles if + proposition, will/would + verbe — une condition et son résultatif I were in your shoes I'd pick
Voix passive be + participe passé — l’accent est mis sur ce qui arrive, pas sur qui le faitwill be answered · is closed · were split
Present perfect have/has + participe passé — une action passée qui compte encore maintenanthave heard · have followed · have faced
Propositions relatives who / which + proposition — une précision sur une personne ou une choseextension which means · patterns which were · thousands which will

Prononciation à surveiller

Le locuteur utilise 8 contractions et formes réduites, comme don't, I'd, isn't. Prononcez-les sous leur forme courte, telles que vous les entendez.

  • Les sons « sh » et « zh »: aggregation /æɡɹəˈɡeɪʃən/, instantiate /ɪnˈstænʃieɪt/, modification /ˌmɑdɪfɪˈkeɪʃən/
  • Mots longs — placez bien l’accent: behavioral /bɪˈheɪvjəɹəl/, aggregation /æɡɹəˈɡeɪʃən/, modification /ˌmɑdɪfɪˈkeɪʃən/, inheritance /ɪnˈhɛɹɪtəns/, architectural /ˌɑɹkɪˈtɛkt͡ʃəɹəl/

Les sons difficiles pour les francophones :

  • /h/ — il se souffle, il n’est pas muet: behavioral /bɪˈheɪvjəɹəl/, inherit /ɪnˈhɛɹɪt/, inheritance /ɪnˈhɛɹɪtəns/, hint /hɪnt/
  • /tʃ/ et /dʒ/ — à ne pas adoucir en « ch » et « j »: magically /ˈmæd͡ʒ.ɪ.kli/, architectural /ˌɑɹkɪˈtɛkt͡ʃəɹəl/
  • /r/ anglais — langue recourbée, sans frotter la gorge: attribute /ˈæt.ɹɪˌbjut/, behavioral /bɪˈheɪvjəɹəl/, aggregation /æɡɹəˈɡeɪʃən/, constructor /kənˈstɹʌktɚ/, formalize /ˈfɔɹ.məlaɪːz/

Comment s’entraîner avec cette vidéo

  1. Écoutez la vidéo en entier une fois sans parler et notez les mots que vous ne connaissez pas.
  2. Commencez à la vitesse 0,75×, répétez phrase par phrase, puis revenez à la vitesse normale quand cela devient facile.
  3. Enregistrez-vous et comparez avec l’original, en faisant attention à des mots comme steak, template, attribute.

Qu'est-ce que la technique du Shadowing ?

Le Shadowing est une technique d'apprentissage des langues fondée sur la science, développée à l'origine pour la formation des interprètes professionnels. Le principe est simple mais puissant : vous écoutez de l'anglais natif et le répétez immédiatement à voix haute — comme une ombre suivant le locuteur avec un décalage de 1 à 2 secondes. Les recherches montrent une amélioration significative de la précision de la prononciation, de l'intonation, du rythme, des liaisons, de la compréhension orale et de la fluidité.

Technique du shadowing : lire le guide complet étape par étape →