Keyword and data types.txt

Hello coders In this blog I will be explaining about some keyword in java

Final keyword
The name itself suggests its meaning in Java.
By using "Final" Keyword we are making the value final or constant 
It can be used anywhere means we can use this keyword for decalaring var,class,function
It can stop method or overriding, Inheritance, value changing of variable
example of final variable
Example:
final int value = 100;
value=200;
OUTPUT: Compile time error
Above snippet will give compile time error because we changing the value of final variable


Import keyword
the import is used to import some built-in libraries like Scanner Class.
which will help us to take the input from the user 
It's similar to the #include preprocessor directive used in C++.
In case we don't use an import statement we have to define the full class name with the object 
Example
If we don't use the import statement for a Scanner class
java.util.Scanner scanner = new java.util.Scanner();
int input = scanner.nextInt();
we have to mention the java.util.Scanner everywhere

If we use the import keyword
import java.util.Scanner;

Scanner sc = new Scanner(System.in);
System.out.println("Enter a Number");
int input = sc.nextInt();

Now above code snippet does not need the java.util.Scanner in every line because we have import keyword we can write it one time and use anywhere in whole code
Don't worry about the Scanner class. I will talk about this in upcoming articles.


Break 
Break is a keyword that helps you exit loops. when your condition is met and dont't want to run the loop anymore
It can be also used if-else blocks
for(int i=1;i<=10;i++){  
        if(i==5){  
            //breaking the loop  
            break;  
        }  }
        System.out.println(i);  
The loop will end when the value of I will be 5 and for loop will end when the value will be 5 by using increment

Continue
Continue is another keyword which is used in java in terms of loops
In above the break keyword breaks loop when condition is met
It continues execution, skipping that specific iteration 
Real world Use case:
Ecommerce platform 
Think about yourself handling a list of orders while working on an e-commerce site. Orders that are listed as canceled or refunded should be skipped.
for countering this problem the continue can be used
for (int i = 0; i < 10; i++) {
if (i == 4) {
continue;
}
System.out.println(i);
}
output:
0,1,2,3,5,6,7,8,9

So as per the above concept the i skips the 4 value and prints every other value

String 
String is a keyword which can used to store sequence of characters 
Strings are immutable, meaning their value cannot be changed after creation
So here we will learn about a concept called String pool
String pool is basically separate memory block where the string literals are stored 
Only string literals, not String objects, are stored in the string pool.
2 ways to declare a string:
Literal : String str = “Nerd”;
Object : String str2=new String("Nerdy");

String pool is a concept in which if there are 2 literals with same value then 2nd literal will hold the reference 
String st="Hello";
String st2="Hello";
String st3=new String("Hello")
Now the first st  will get memory allocation and other st2 will hold the reference of st 
Now this approach will help to save the memory 
Note this applies to String literal not the Objects of string.

New Keyword
New is a keyword that is used to create an object(instance) of a class 
The new keyword allocates memory for an object instance of a class
A detailed exaplination of how new works and how an object is created is also uploaded 
Kindly go and check the blog with the Object creation

Example=
public class MyClass {
void display() {
System.out.println("Invoking Method by using the object");
}

public static void main(String[] args) {
MyClass obj = new MyClass();
obj.display();
}
}



Keyword or datatypes
Primitives
Int=Can be used to store number data 
can't store Decimal value
Example
int i=10;

Float
Can be used to store the deimal number data
Example:
float f=10f; //the  f suffix indicates that it is float value


Boolean
Can be used to store the TRUE or FALSE Value
boolean bool = true;

Char 
Can be used to store the  single character
char c = 'A';
Note =compiler will give error if you store multiple error
char a="abc";

double
Used for storing decimal numbers with higher precision than float
double provides higher precision than float, making it suitable for most decimal number calculations.
example:
double radius = 5.0;
double area = Math.PI * radius * radius;
System.out.println("Area of the circle: " + area);
Be aware of potential rounding errors when working with floating-point numbers.