#6 Data types in Java

Summary

This video script delves into the concept of variables and data types in Java programming. It explains the two categories of data types: primitive and non-primitive, focusing on the former. The script outlines the four main primitive data types: integers, floating-point values, characters, and Booleans. It further breaks down integers into byte, short, int, and long, detailing their storage sizes and value ranges. The video also clarifies the use of 'float' and 'double' for floating-point numbers, the importance of using single quotes for characters, and the strict true/false values for Booleans. The script aims to familiarize viewers with the nuances of variable declaration and data type usage in Java.

Takeaways

• 😀 Variables are used to store data in programming, and they are created using a data type and a value.
• 🔢 In Java, there are multiple data types available for storing data, which are categorized into primitive and non-primitive data types.
• 📏 Primitive data types are further divided into integers, floating-point values, characters, and Boolean values.
• 🔢 Integers can be of different subtypes: byte, short, int, and long, each with specific memory sizes and value ranges.
• 📉 Floating-point values include float and double, with float being limited in precision compared to double.
• 🔤 Characters in Java are stored using two bytes, supporting Unicode to represent a wide range of characters from different languages.
• 💡 Boolean data type can only have two values: true or false, and it's used for logical conditions.
• 🛠 When declaring variables, it's important to match the data type with the correct value and notation, such as using 'L' for long integers and 'F' for float values.
• ⚠️ Errors can occur if the value assigned to a variable exceeds the range supported by its data type, such as assigning a value too large for a byte.
• 💻 Understanding the size and range of each data type is crucial for efficient memory usage and accurate data representation in programming.

Q & A

What are the two categories of data types in Java?

The two categories of data types in Java are primitive and non-primitive. The script primarily discusses primitive data types.

What does the term 'primitive' mean in the context of data types?

Primitive, in the context of data types, means that the data type is basic and simple to use, directly supported by the Java language.

List the four main categories of primitive data types in Java.

The four main categories of primitive data types in Java are integers, floating-point values, characters, and Boolean.

What are the subtypes of the integer data type in Java?

The subtypes of the integer data type in Java are byte, short, int, and long.

What is the size and range of the 'int' data type in Java?

The size of the 'int' data type in Java is 4 bytes (32 bits), and its range is from -2^31 to 2^31-1 (-2,147,483,648 to 2,147,483,647).

Why would you use the 'byte' data type in Java?

You would use the 'byte' data type in Java to save memory when you need to store a smaller number within the range of -128 to 127.

How do you define a floating-point number in Java?

In Java, to define a floating-point number, you can use 'float' or 'double'. By default, a number with a decimal point is considered a 'double', but you can specify 'float' by appending 'f' or 'F' to the number.

What is the difference between 'float' and 'double' in Java?

In Java, 'float' takes 4 bytes and has a limited precision, while 'double' takes 8 bytes and provides a higher precision, which is suitable for scientific calculations.

How do you define a character variable in Java?

To define a character variable in Java, you use the 'char' keyword, followed by the variable name and a single quote around the character, for example, `char c = 'K';`.

What are the valid values for a Boolean data type in Java?

The valid values for a Boolean data type in Java are 'true' and 'false', with no numeric equivalents like 0 or 1.

What is the significance of the 'l' suffix when defining a long integer in Java?

The 'l' or 'L' suffix, when used with an integer, signifies that the number is of the 'long' data type, which requires this suffix to differentiate it from other integer types.

Outlines

00:00

📚 Introduction to Data Types in Java

This paragraph introduces the concept of data types in Java, explaining the difference between primitive and non-primitive data types. It emphasizes that primitive data types are simple and basic, used for storing various kinds of data such as integers, floating-point numbers, characters, and boolean values. The paragraph further categorizes primitive data types into integers, floats, characters, and Booleans, and discusses the subtypes of integers, including byte, short, int, and long, along with their respective sizes and ranges. The explanation includes how to declare variables of these types and the significance of using the correct data type based on the range of values they need to store.

05:00

🔢 Deep Dive into Numeric Data Types

The second paragraph delves deeper into the numeric data types available in Java, specifically focusing on the integer and floating-point types. It explains the default sizes and ranges of int, byte, short, and long, and how to calculate their value ranges. The paragraph also discusses the floating-point data types, float and double, highlighting their default values and precision. It clarifies that in Java, double is the default floating-point data type due to its higher precision. The explanation includes how to explicitly declare float variables to avoid implicit conversion from double and demonstrates the process of creating variables with different data types, including byte, short, long, float, and double, with examples and potential compilation issues.

10:01

🔤 Exploring Character and Boolean Data Types

The final paragraph covers the character and Boolean data types in Java. It explains that characters in Java are stored using two bytes following the Unicode standard, allowing for a broader range of characters compared to other languages that might use ASCII. The paragraph demonstrates how to declare a character variable using single quotes and highlights the difference between characters and strings. It also discusses the Boolean data type, which only accepts true or false values, and the correct way to declare Boolean variables. The summary includes practical examples of declaring variables for each type, along with a compilation test to ensure the code is error-free. The paragraph concludes with a reminder of the importance of using the correct data type for the intended purpose and the impact of practice in becoming proficient with Java's data types.

Keywords

💡Variable

A variable in programming is a storage location paired with an associated symbolic name, which contains some known or unknown quantity of information referred to as a value. In the context of the video, variables are used to store data of different types, such as numbers, characters, or boolean values. The video script discusses how to create variables with specific data types and values, emphasizing their importance in programming.

💡Data Type

Data types in programming define the kind of data a variable can hold. The video script explains that there are two main categories of data types: primitive and non-primitive (reference types). It focuses on primitive data types, which are the most basic types of data and include integers, floating-point numbers, characters, and booleans. The script further elaborates on the different primitive data types available in Java, such as int, float, char, and boolean.

💡Primitive Data Type

Primitive data types are the basic data types in Java that are supported by the Java language and are used to define variables that can store only one value at a time. The video script discusses several primitive data types, including integers (int, byte, short, long), floating-point numbers (float, double), characters (char), and booleans (boolean). These types are fundamental to understanding how data is stored and manipulated in Java.

💡Integer

An integer is a whole number, positive or negative, without decimals, that can be represented in a computer's memory. In the video script, integers are one of the primitive data types, and the speaker explains that integers can be stored using different subtypes like byte, short, int, and long, each with its own size and range. The script uses examples to illustrate how to declare and assign values to integer variables.

💡Floating-Point Value

A floating-point value is a number that includes a decimal point and can represent real numbers. The video script distinguishes between two types of floating-point values in Java: float and double. It explains that float values are typically used when precision is less critical and memory conservation is important, while double values are used for higher precision calculations.

💡Character

A character data type is used to define a single 16-bit Unicode character in Java. The video script explains that characters in Java are stored as two bytes, allowing for a wide range of characters from different languages. The script demonstrates how to declare a character variable using single quotes and assigns a character value to it, such as 'K'.

💡Boolean

A boolean data type can have only two possible values: true or false. In the video script, booleans are used to represent logical conditions and are essential for control flow in programs. The script clarifies that in Java, boolean values are not represented as 0 and 1 but explicitly as true or false, and they are used for decision-making in code.

💡Byte

A byte is a data type that can hold a small range of integer values, typically from -128 to 127. In the video script, the byte data type is introduced as a subtype of integer that is useful for saving memory when dealing with small numbers. The script provides an example of declaring a byte variable and assigning a value within the permissible range.

💡Short

A short data type is an integer type that occupies 2 bytes of memory and can store values ranging from -32,768 to 32,767. The video script mentions short as a subtype of integer, which is useful when the range of int is excessive for the required values, thus conserving memory.

💡Long

A long data type is an integer type that occupies 8 bytes of memory and can store larger integer values than int. In the video script, long is introduced as a subtype of integer for storing very large numbers. The script demonstrates how to declare a long variable by appending an 'L' to the assigned value to indicate that it is a long literal.

💡Double

A double data type is a floating-point type that occupies 8 bytes of memory and can store a wider range of values than float. The video script explains that double is the default floating-point type in Java and is used when high precision is required. The script also clarifies that when assigning a floating-point number without an 'F' suffix, the number is treated as a double.

Highlights

Introduction to creating variables with data types and values in Java.

Explanation of primitive data types in Java and their categorization.

Discussion on integer data types, including byte, short, int, and long.

Detail on the size and range of integer subtypes and their use cases.

How to calculate the range of byte data type in Java.

Floating-point data types float and double, with a focus on default types in Java.

Clarification on the precision and storage size differences between float and double.

Demonstration of creating a float variable with explicit type declaration.

Introduction to the character data type, its size, and Unicode support in Java.

How to define a character variable in Java, including the use of single quotes.

Explanation of the Boolean data type, its values, and usage in conditions.

How to define a Boolean variable and the importance of using true or false, not 0 or 1.

Practical examples of declaring variables of different data types in Java code.

Compilation errors and how to resolve them when assigning values to variables.

The significance of using the correct data type for the intended value range.

Final thoughts on the importance of practice for mastering variable and data type usage in Java.

Transcripts

so now we know what variables are and

how do we create them so basically in

the last video we have talked about how

to create a variable with the help of

the data type and the value as well now

what are the other options we have so we

have worked with int right do we have

other options so basically we have

multiple data types to store your data

so let's talk about the first thing

which is uh data type in fact there are

two categories of data type which we can

normally work with one is called

primitive and the other one will be

we'll keep it question mark okay at this

point we are not just discussing about

the second one the first one is

primitive so basically in Java we have

lot of inbuilt data types available

which you can use and they are primitive

now primitive simply means it is simple

basic to use to work with so whatever

data you normally have normally we work

with numbers we work with Point values

we work with characters we work with

true or false now for that we have this

that category so we can divide primitive

into four categories here uh the first

way one the first one is of type

integers the second one we have is float

floating point value basically so we can

say float and the third one is

characters and the fourth one is your

Boolean of course when you divide this

we have more categories to it but in

general we have four we have integer

float character and Boolean now when you

say you want to store a range a negative

range to positive range numbers normal

numbers or natural numbers you can say

in fact we can we can call them as

integer itself because we are starting

with negative value so that goes into

integer whenever you have Point values

with that goes into float value whenever

you go with characters like a b or any

Regional characters you have all across

the world that goes into character and

then when it comes to true and false we

go with Boolean now inside integer

itself we have multiple subtypes to it

uh we have a concept of byte we have

short we have int and we have Long Alpha

float we have another option which is of

double and of course we have float and

then carries characters are character so

in characters we can have different type

of character factors in Boolean the only

values we can have is true and false

okay so example if I go back to my code

and if I want to create a different

variable this time let's say float so I

can just come back here I can remove

this section and here I can say this we

are creating a float value now how do we

get a float value base so we can simply

say float and then we can have a value

that says 7 or we would name to it right

so name we can have is marks of course

we don't put in marks but let's go with

marks and then we can go with a value

now floating Point values will be having

a DOT right so we can say 6.5 something

like this some float marks equal to 6.5

that makes sense right okay cool in the

same way we have also mentioned we have

subtypes to integer we can have a byte

format but why do we need all this extra

formats for that let's understand uh

some basic concept now basically when

you talk about integers itself so if you

talk about integer we have some sections

to it so integer will have different

part so integer will have different

sizes example if you want to store a

normal number so in general we always go

with int and int has its own value okay

so when you talk about int the size of

int is is four bytes so we can say 32

bits and then it has a range to it and

you can find the range on the screen uh

we also have a format which is let's say

if you want to store a bigger value a

very big value so in this case I'm of

course a value goes beyond that range we

have to go for the long format now long

supports eight bytes now of course when

you have more parts it will it will

occupy more values and it will have a

range so of course you can find the

range on the screen now what if you want

to store a smaller number so of course

int provides you that range but then

what if you want to save memory you

don't want to go for end range in that

case we can have a short value now short

is only two bytes so if you want to have

a limited range you can find the range

on the screen and then we have the next

range which is of byte now byte is only

one byte okay so eight bits and whatever

you want to store you can store in that

of course it has its own range now how

do we calculate this range so we do with

the help of it goes from negative values

right so it is minus two raised to 8 2

plus 2 raised to eight minus one okay so

which is 2 s to 8 is what it is okay

starting with negative value right so

just two is to 7 and 2 is to 7. and the

range is so how do we calculate version

7 is 128 so it starts from minus 128 to

plus 127 so 128 minus 1 127 that's how

you can calculate the range for all the

other numbers and you can of course you

have seen that on the screen so this is

how we can use integer so which one to

use so if you want to get a variable

which is a which will have a value let's

say five or six or maximum 127 you can

go for byte now how do you get that

variable it's very simple you use a type

which is byte you specify a variable

name let's say num and you assign a

value which is eight or any other value

which you want of course that should be

in a Range and that's how you can store

it now what if you want to have a float

value now float actually gives you two

different values or two different types

now it depends upon which programming

language you have worked with before

example if you have ever worked with CVA

by default we have a value which is

float so by default we have float there

now float only takes four bytes and it

has its own values you can store and

then we also have option of double which

takes eight bytes now what you think

which will be default value think about

it will it be float or double by default

in Java so default is actually double

not float okay now why double is because

see float are good when you have limited

values when you have limited Precision

because after your point value example

if you have value which is

126.5678 or whatever values you have so

float will have a limited Precision set

here but on the other hand double will

have a longer one right so double can

have more values so whenever you perform

scientific calculations or any kind of

calculation if you wanted to make it

fast and it should support maximum

Precision you can use double there right

and by default Java supports double so

if you want to create a variable which

is with double so you can simply say

double and you can create a variable

name num is equal to you can assign a

value which is 5.6 so whatever value you

want to assign but how about float now

if you try that with float it will it

may not work example if you say float

and if you say a variable name which is

num and equal to so when you try to

assign 5.6 it will give you error it's

because by default the moment you say

Point values it will be considered as as

double and if you want to say hey I

don't want to work with double I want to

work with float so explicitly you have

to mention hey okay this is actually

double value so you can this is actually

a float value so you can put a f there

right so 5.6 F that's how you define

it's a float value for double you don't

have to mention that now how about

character so when you when you work with

character and in other languages

character will have a less bits but in

Java it goes for two bytes so so in

other languages like C you have only one

byte it's because it normally occupies

the integer range it normally occupies

the character range ASCII values but

then in Java we thought hey can we just

have all the characters in the world not

just English all the languages so Java

actually follows something called

Unicode not ASCII by default it will

support Unicode and it has two bytes

which is 16 bits so it has a bigger

range right so this is a range it

normally works with so of course you can

work with any type of values you have

and any type of characters basically you

have and if you want to define a

character variable it's very simple you

say Cad and then you specify the

variable name let's say character or c

equal to whatever character you want to

assign let's say I want to assign a

character which is K now in this K in

this case if you want to work with a

character can we use double Quotes no

double quotes is for string right for

character we have to use single quote

and you have to put your character to

single quote and remember it will only

accept a single character and next we

have of type Boolean so if you want to

work with Boolean Napoleon will only

accept true or false okay no other

there's no subtypes here only true or

false now one thing you have to remember

now in other languages it may represent

it with the help of one and zero in Java

we don't do that so in Java it does not

it doesn't work with zero and one it is

true and false this Knight like true is

one and false is zero it's only true and

false it is normally used for conditions

if you want to check for the condition

based on that you will do something

that's what we can use two and false I

mean think about computers when you say

computer can think it's because of this

true or false okay and how do we Define

a Boolean variable so it's very simple

you use a keyword called Bull and then

you mention a variable name let's say B

is equal to you either assign true or

false okay you don't have to put a semi

a single quota double quote because they

are itself keywords so these are the

options we have now if you want to see

this in a code it's very simple you can

just go back here and say okay byte is

done let's create some variables with

different type so ain't we have already

seen so it's a number one this is how

you assign integer value what if you

want to go with a byte so you can say

byte B I will say b y equal to now can I

assign a value which is 129 you can say

it will give you if I do that if I go

back to my compiler compile you can see

it will give you error it says possible

lossy conversion from into byte so this

is int which is 129 it will if you try

to save that in a byte it will not work

but what if you say 127 that's the last

value you can store compile okay this is

a problem with result let me just remove

this section and compile no issue okay

so this is how you save byte value what

if you want to store shots you can say

short sh equal to

and you can assign value which is let's

say five five eight any even number

doesn't matter and then what if you want

to work with long so long L is equal to

now when you work with long remember

this thing after every number for long

you have to put a l at the end to

specify that's a long number the thing

we have done with float we have to put F

in the same way long needs l

and what if you can do here with float

so you can say float f is equal to

5.8 okay let's try with 5.8 and let's

see what happens if you try to compile

this compile okay you can see it is

giving you it says again possible logic

conversion from double to float because

by default 5.8 is double if you want to

mention hey that's not double that's

float you can put a f at the end that

should work you can work with double as

well Double D is equal to 5.8 same value

but this time it is double and then what

else we can work with we can work with

character as well so we can say care C

is equal to in single code you can

mention a character k then we can go for

Boolean which is Boolean in this case

and you can say B is equal to True

simple stuff right uh let's try to

compile this of course we are not

printing anything so we don't expect

anything on the console compile or

there's an error it says cannot find

symbol bull okay my bad it is Boolean

the only problem is when you work with

multiple language at the same time you

get confused somewhere so that that's

Boolean notable so in the notes as well

I need to change it so I will say this

is Boolean

cool and now let's compile this once

again compile okay there's no problem

and let's run this of course it will run

but then you will not see any output

right no output because we're not

printing anything so yeah that's about

this we have different type of

data types we can work with and all

these are inbuilt apart from this we

also we also have some more data types

which we'll see later they are not type

of primitive but this is primitive data

types and this is working okay awesome

so now we know what what variables are

what data types are what a size or range

of each data type here and you don't

have to buy hard them you will get used

to it the more practice you do with this

variables you will get used to when to

use what but what if I remove that

single code there let's try compile and

you can see we got another we can't even

put double quotes there it will give you

as well and you can see you can't even

put double code so you have to put

single code because that's how that's

what character represents and the

character can be numbered as well so you

can put a character here which is eight

which is the character itself right

digital also character no other cool so

yeah that's it from this video