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diff --git a/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/16 - Class Diagram: Relationships - lang_en_vs5.srt b/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/16 - Class Diagram: Relationships - lang_en_vs5.srt deleted file mode 100644 index ef6550d..0000000 --- a/usth/ICT2.7/P2L2 OO Software Engineering and UML Subtitles/16 - Class Diagram: Relationships - lang_en_vs5.srt +++ /dev/null @@ -1,111 +0,0 @@ -1 -00:00:00,130 --> 00:00:02,620 -And that's exactly what we're going to look at next, - -2 -00:00:02,620 --> 00:00:05,630 -relationships in the class diagram, how they're represented and - -3 -00:00:05,630 --> 00:00:08,010 -what they mean. First of all relationships as the - -4 -00:00:08,010 --> 00:00:12,550 -name says, describe interactions between classes or between objects in - -5 -00:00:12,550 --> 00:00:15,510 -my system. And we will describe three main types - -6 -00:00:15,510 --> 00:00:19,060 -of relationships. The first one is called a Dependency - -7 -00:00:19,060 --> 00:00:22,450 -relationship. And we can express that as X uses - -8 -00:00:22,450 --> 00:00:25,840 -Y and we represent it with a dashed directed line. - -9 -00:00:25,840 --> 00:00:28,170 -So when we have such a line between two classes - -10 -00:00:28,170 --> 00:00:31,020 -that means that the first class uses the second one. And - -11 -00:00:31,020 --> 00:00:33,520 -we're going to provide an example of a dependency in a - -12 -00:00:33,520 --> 00:00:37,960 -minute. The second type of relationship is an association that can - -13 -00:00:37,960 --> 00:00:40,880 -also be an aggregation. We'll see what the distinction is. - -14 -00:00:40,880 --> 00:00:43,470 -But basically, what this means is that we can express that - -15 -00:00:43,470 --> 00:00:47,640 -as a X has a y. So x contains a - -16 -00:00:47,640 --> 00:00:50,950 -y. And if it is in association, we indicate it with - -17 -00:00:50,950 --> 00:00:53,570 -a solid undirected line. If it's an aggregation, - -18 -00:00:53,570 --> 00:00:55,740 -we indicate it in the same way, but with - -19 -00:00:55,740 --> 00:00:58,510 -a diamond at one of the ends. Finally, the - -20 -00:00:58,510 --> 00:01:02,740 -third type of relationship is what is called Generalization. - -21 -00:01:02,740 --> 00:01:05,300 -And this can be expressed as x is a - -22 -00:01:05,300 --> 00:01:09,620 -y. So this is the relationship that expresses inheritance. - -23 -00:01:09,620 --> 00:01:13,600 -Specialization between two classes. It's represented with a solid - -24 -00:01:13,600 --> 00:01:16,190 -directed line with a large open arrow head at - -25 -00:01:16,190 --> 00:01:19,030 -the end. Going from the more specialized class to - -26 -00:01:19,030 --> 00:01:21,770 -the less specialized class. So going from the subclass to - -27 -00:01:21,770 --> 00:01:24,740 -the super class. So now let's look at each relationship - -28 -00:01:24,740 --> 00:01:28,360 -in more detail using our example, our course management system. |