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Let's not look at box primitives if you recall we discuss them briefly while learning about switch fragments

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not to learn more about them and see how they are useful in Java.

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We have these eight primitive apps on each of them has an associated class called a box primitive the

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box perimeter corresponding to an integer and you can see the rest here.

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These boxes tomatoes are part of the job product line package.

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So Boxborough model is simply a class and it is called as a box model as it and causes a primitive value

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.

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And let's see what that means.

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As you can see from these examples each box perimeter was created by passing a corresponding primitive

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value boot's constructor in the first example an instance is created by passing an integral.

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Similarly in the second example a boolean that really is passed to create a boolean instance in the

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third example.

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We are creating a character instance when the example creates a double.

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We can also pass a primitive as a string as shown in the first example where quantified was passed as

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a string.

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Not that all of them except upper class X substring as in front of the last example shows that the value

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passed as a string must be valid in this case we are passing it as an English word under generates an

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error at runtime abox perimeter is also referred to as a proper class as it wraps the perimeter.

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No let's look at some uses of box primitives that are useful in converting strings to primitives.

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Here's an example that shows how to convert a string into an int.

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It's an extremely useful utility matter.

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These classes also provide several useful public static views.

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For example all numeric primitives.

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How Markson min values.

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And if you need to know the max Aardman value of a particular model then we can use a max underscore

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value.

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Aardman underscore value fill in the corresponding box perimeter box primitives.

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Also provide several other useful utility methods for example character class has tons of methods that

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perform boolean checks on input car perimeter.

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One example is to check whether an input car is a letter or a digit.

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Another interesting example is the boot binary string method from the integer on long classes.

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It returns the binary representation of the input argument as a string.

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You may never use it but it's just nice to know that there is such a method.

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Next boat double and float classes have a method called ees none which remains true or false depending

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on whether the argument passed is a non or not.

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So basically baulks primitives provide some useful methods and fields related to each Mamadu.

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That's their fundamental use but primitives are also useful in other contexts.

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For example box primitives are useful in populating data structures like idlest and hash map.

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This is because we cannot add primitives directly to such data structures.

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Let's look at an example.

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Here we are first creating an instance of idlest that is used to store elements like an array but it

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need not be of fixed size.

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Next we are adding a primitive undefined to the creator or ArrayList Partridge R5.

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This would be a compiler error as do destructors like other list or Mr. object references so they don't

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allow storing parameter variables are promotable it grows directly as shown in the next statement.

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You would have to wrap the perimeter in a box Amodeo to store it in the ironist Angela 5:01 words.

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It would be possible to add primitives credit structures like ironist and it is to be a feature called

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arbo boxing which we will discuss next.

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But even with this feature Behind the scenes the corresponding box model is what gets added next.

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They are also used in genetics when defining something called parameterized types but let's not worry

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about it for now as it will be clear when we get to generics.

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Let's not look at few commonly used methods.

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We will just look at methods in the integer class as other wrapper classes also have similar methods

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Sarbox perimeter wraps up at him or do not want to extract the portmanteau out of the box Plimmer do

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.

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Then we can invoke the in value method.

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That is it unwraps the box primmer to here variable i gets assigned the parameter up if.

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Like I just mentioned other upper classes also have similar methods.

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For example boolean class has boolean value character classes Carbajal and so on.

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You can see that these matters are meaningfully named.

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One example when we look at Int value are boolean value that terms end or boolean such suggest that

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we are requesting to return the proper value as an end.

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Or boolean primitive.

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That's all we can remember these methods and value would return in Primitivo boolean value would return

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a boolean perimeter.

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You would read on a carpet Amatil unsworn next is about parsing strings that is in what would be a string

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and you need to convert it either into a premier or a box or two.

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One would use cases when double up in data integration software and you have to integrate data from

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different partners.

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This would typically involve communicating with Web services which expose data in the form of X-amount

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objects on.

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And you would have to parse their data using an appropriate parsing library.

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For example if you're parsing some sort or document you may have to extract the artery which is represented

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in an X someone aliment as shown here.

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And this gives you would Fosset extract the Order ID using an X symbol parsing library like Jerome and

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the extracted that ID would be in string format and you would have to convert it into an integer before

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further processing.

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So if you have to convert the string into a remedy and then you would use this static matter parsed

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in once again like in the previous method in value here in in part and suggest that we are seeking an

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end perimeter and the term parsed would always mean that we are parsing some kind of a string.

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But to convert the string into a box primmer do you would use a static method value or Again similar

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methods are available in other wrapper process Ghalibaf is a standard naming convention for methods

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that create objects.

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In this case we are creating an integer object such a method is referred to as a simple factory on the

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naming conventions.

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Listen we will also look at other names that can be used for such methods.

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So value of means object creation.

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Next if you want to convert the primitive and into a string then you would invoke the static string

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method and pass the parameter as an argument.

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So as a matter name suggests it simply convert something into a string.

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We have seen how a box but a model could be created but passing a parameter to the constructor.

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However Alternatively you can use this static value of matter.

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So once again we are using a value of method as we are creating an object previously took string as

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input.

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But this time it is taking a parameter as input.

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Not that performance wise.

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Creating an object the other value of motard can be significantly better compared to creating it.

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Are the constructor.

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The reason for better performance is due to internal caching that in bigger crost us the values in the

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range minus 128 to 127 are always.

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There is indeed integer instances but these values are stored in memory.

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So if we try to create an integer instance in this range using the value of method then the method would

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simply return an instance from the cache that is it is not creating a new instance.

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It is kind of similar to string one word string literals were getting gassed.

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Let's quickly took all the source code of this matter just to get a free love.

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How caching is done here.

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OK here is the value of motard from the entire class and we are here in the group Code website and I

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got here by googling for grep code space integer.

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OK on the radio amateurs is taking a permit you are returning an integer instance which is a Boxborough

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motto on the method itself is a static method.

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So us we are checking if the input parameter is in between minus 128 and positive 137.

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If that's the case then we are returning it pre-created embetter instance.

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So we are not going to create a new integer instance.

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OK so we are going to use the one from cache.

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OK and if that's not the case.

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If it is outside of this range then we are creating new integer instance or here.

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Now so this is basically an R is simply an array of integer instances.

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OK so let me just click on that or here.

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Here is where the R is getting created.

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So it's named as underage and it has integers India or instances and this is the size of the array over

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here and it is being initialized within the static initializer.

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OK this is where it is getting initialized.

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OK so if you recall from our discussion on static initializers been needed one of the use cases was

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we needed.

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If we have if we cannot initialize in a single line.

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So as you can see we need a first statement here so we have to use a static initializer for doing that

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.

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OK now this particular code gets in worked when the integer class is used for the very first time.

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That's when it gets loaded into memory and that's when the static initializer block on this particular

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statement.

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Everything gets executed but that we will see in the JVM and another chapter.

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While looking at clustering process.

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OK so as you can see here we have this anti-Yoko the cache which is an array of indigo instances and

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we are populating it here.

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And that's about it.

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So that's about Boxborough meadows and it is likely that you will use them quite a bit in your professional

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life.

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Thank you