Keywords in Java are something that has got a special meaning. It is a predefined word which has special meaning in Java and these words cannot be used as object reference, variables, or data member.
Example: If we want to store a numeric data, we use a keyword called “int” If we want to store a character value, we use char keyword. If we want to store a decimal value, we use either float or double keyword.
Total numbers of keywords in java
We have a total of 53 keywords in java.
In which, 3 are literals or constant value such as true, false, and null. And on the remaining 50, we don’t use 2 keywords in java ( goto and const) .
The list of 48 keywords is as follows.
1. abstract
It used in two contexts, class and method.
- An abstract class is a class which declared with abstract keyword. It is just like a simple class having data members, constructors, methods along with that we can also declare the abstract method in this class.
- An abstract method is a method that does have any implementation or definition or logic. This type of method is declared with an abstract keyword just like an abstract class.
2. assert
3. boolean
This keyword in java used to indicate a data type that can hold True and False values only.
4. break
It is a control statement that used to come out from loops after certain conditions achieved.
5. byte
It is a datatype in java which used to store the numeric value of up to 8 bit.
6. case
This keyword in java used with a switch statement.
7. catch
It used which a try block, if any exception occurs inside the code written under try block, then catch block will handle the exception.
8. char
It used to store the character datatype in Java.
9. class
This keyword in java used to create or declare the class.
10. continue
It generally used with a loop and the purpose of the continue keyword is to Sends back the control outside of the loop.
11. default
It used with the switch case statement, if the switch argument does not match with any of the mentioned cases then control swift to the default statement.
12. do
Generally, it used with the do-while loop. In this case, before starting a loop, the very first condition is always true.
13. double
It is one of the datatypes in java which holds the numeric value up to 64 bit.
14. else
It used with the if statement. The condition of if the statement is false then control will be moved to else part.
15. enum
16. extends
It used to inherit the other class. If any class having extends keyword that means it is the sub or derived class of some other class.
17. final
The final keyword in java has two meanings, one for class and other for data members of the class.
- If any class declared with the final keyword that means this class is not eligible for inheritance. Hence there will be no subclass or derived class for the final class in java.
- Any data member declared with the final keyword that means once the value assigned to it, then that not going to change in a further line of code.
18. finally
This keyword used with the try-catch block, even any exception arises the code written in finally block will get executed.
19. float
It is also a data type in java which is used to hold 32-bit value.
20. for
It used to initialize a for a loop.
21. if
Tests a true/false expression and branches accordingly.
22. implements
It used with the class to implement any interface.
23. import
When you want to use other classes in different class files, then import keyword used for this purpose.
24. instanceof
It is a keyword that is used to check the Object type. It returns the boolean value that is True or False.
25. int
It is used to store the 32-bit numeric value of the integer type.
26. interface
This keyword in java is used to declare the interface.
27. long
A data type that holds a 64-bit integer
28. native
It indicates that a method is implemented with native (platform-specific) code.
29. new
It is used to create an object in java. This new keyword gives the direction to JVM to create an Object.
30. package
Used to Declares a Java package.
31. private
An access modifier indicating that a method or variable may be accessed only in the class in which it declared.
32. protected
It is also one type of access modifier. The scope of any data member or method is up to package level when that declares with a protected access modifier.
33. public
The data member or method which declares with public access modified can be accessed from anywhere in java even outside the package.
34. return
It is a last executable statement in any method, which basically use to return some value if the method get invoked.
35. short
A data type that can store a 16-bit integer
36. static
The static keyword in java used to declare the method or variable is of Class type. That is method or variable which declares with a static keyword can be called with the Class name.
37. strictfp
This Java keyword used to ensure that the floating value calculation is always the same on every platform.
38. super
Refers to a class’s base class (used in a method or class constructor).
39. switch
A statement that executes code based on a test value.
40. synchronized
It indicates critical sections or methods in multithreaded code.
41. this
It represents the current invoking or class Object.
42. throw
Creates an exception.
43. throws
Indicates what exceptions may be thrown by a method.
44. transient
It used to Specifies that a variable is not part of an object’s persistent state.
45. try
Starts a block of code that will be tested for exceptions
46. void
It used with the method and indicates that the method does not have any return type.
47. volatile
Indicates that a variable may change asynchronously.
48. while
Starts a while loop.
Summary
In this article, you learned about all the available keywords in java which frequently used while writing a program or developing any java based production-ready application. You can also refer to the official pdf link of Keywords in Java.
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If you find any mistake or any feedback, let me know. You can also check out my other articles such as Abstraction, Encapsulation, Inheritance, etc.
