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So we looked at naming conventions next just part of coding conventions let's learn about how to structure

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our programs so we'll see some valuable recommendations and we will also look at one effective July

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item in this lesson.

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Let's begin with class organization.

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And here is the order in which we need to place a Red Cross members disorder was prescribed by Sun Microsystems

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on most of the standard Java classes do seem to follow this pattern.

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Added up the variables with static variables being placed before instance variables we didn't have all

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the static stuff there is static initializers followed by something called static nested classes which

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would be followed by static methods static master classes will be discussed towards the later part of

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the course.

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Next we have the instant stuff that is instance initializers followed by constructors which are followed

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by instance nested classes are in done followed by the instance methods.

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So that's a long list but if it helps just memorize or display at the top we always have variables after

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which we have the static stuff which is then followed by the instant stuff on Witan the static an instance

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actions we have initializers followed by nested classes followed by methods.

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Next is related to class size.

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The most important thing about designing a class is that it should represent single responsibility.

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And this is a very important design principle and the galiot as the single responsibility principle

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.

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So it shouldn't have more than one responsibility when designing your classes.

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If you think about restricting them to single responsibility then it could help in creating better abstractions

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.

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That is you would very likely have several loosely coupled classes and such loosley couple classes promote

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reusability.

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There isn't a strict consensus but usually you don't want your class to exceed 2000 lines probably even

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when it gets two thousand lines or so.

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You may want to rethink about the classes responsibility and see if there is a need for further speedup

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of the class.

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Next let's look at methods.

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It's very important to keep our methods very small unfocused.

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This should do only one thing or no more.

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There is a very popular book called clean code and it actually recommends that method should hardly

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ever be 20 lines long motile methods that are small unfocussed would help in picking a good descriptive

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method names.

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If a method is long.

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See if you can refactor it into smaller matters and enroll them from this method.

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It promotes software use as despoiler amateurs might be useful elsewhere.

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Mono the origin or longer method would be a lot cleaner and also readable.

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Will you give this example when introducing methods on the left we have this search method.

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This is just a search for a given item in a given and added.

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The method has several lines of code representing two main steps in that to come.

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First up would solve the array.

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The second step would perform a binary search on the socket at it instead of having this and dialogic

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in the single method.

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We can move the sorting and the binary search code into their own methods and invoke them as shown here

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.

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The search matter is no much cleaner and with a single glance one may easily understand how the search

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algorithm works.

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It is also recommended to group methods that perform similar actions.

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For example if you look at source code of string class you will notice that all the substring methods

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are grouped together as they perform similar kind of action.

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Similarly an index of methods are also grouped together.

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Next is about local variables.

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Under advice comes from a set of Djala I can Forty-Five which says minimize the scope of local variables

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.

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The items is that the most powerful technique is to declare a local variable when it is fussiest.

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And here is an example.

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Here the method go has around 50 lines of code following with the method freezing work.

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An argument.

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The variable D is declared right about the invocation statement.

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However had we declared the variable early in the method it could affect readability.

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And here is the same example.

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But the local variable b is not declared at the beginning of the matter.

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Now someone is looking at this code.

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By the time they get to the statement that's invoking method foo.

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He or she may not recall the variable by Autard initial value.

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Apart from readability minimizing variable scope is also useful in preventing bugs.

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For example for loop automatically minimizes the scope of variables and dupa this.

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It is preferable to use for loops instead of by laws.

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Let's understand just one example where the for loop preventible.

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Let's consider this code fragment.

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Here we are just creating an array by invoking get random perimeter between it and a fixed array with

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random numbers are in size as indicated in the method argument.

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Next we simply read the array and pass each R element to the matter.

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Note that index is incremented in the matter in location statement itself.

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Let's assume that the user didn't copy and paste this code somewhere below in the same method and renames

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the added to the list too and also renames inexpressible idealogy.

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Now the user makes a copy and paste error as he or she forgets to rename the variable i in the right

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state mental condition expression and the result of this mistake is that the loop never gets executed

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.

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That's because I got incremented to three.

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Jupiter Do I look under that is the condition expression in the second by look first right.

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So there is no completion error and it has potential to go undetected even during runtime which could

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be dangerous in real world system.

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No the same code was rewritten using for each statement.

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Then we wouldn't have this bug here the second for loop also has a copy and paste error where I was

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again not renamed Pejic.

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So G was never declared and so compiler would indicate this right away.

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Even if the user did not want to rename I do J.

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In the second for loop then everything would still work fine as variable i.e. scope is localized to

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both the frontal lobes model within the while loop example.

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The ice core is not ending with the why loop and it may be accidentally used somewhere down in the same

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method and the result of this could be disastrous.

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So variable scope is one reason to prefer four loops over why lobes but readability is also another

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reason.

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As you can see that 4 is much more cleaner looking good and that's about it with regards to how we can

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structural classes and methods.

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Next we will look at conventions that are more focused on stylistic aspects like indentation.

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Thank you