Java’s reserved terms are also referred to as keywords. The words that make up a keyword serve as the code’s opening. Java has standardized these words, thus they cannot be used as variable, object, or class names.
A list of Java keywords or reserved words is given below:
1. Abstract:
Java abstract keyword is used to declare an abstract class. An abstract class can provide the implementation of the interface. It can have abstract and non-abstract methods.
2. Boolean:
Java boolean keyword is used to declare a variable as a boolean type. It can hold True and False values only.
3. Break:
Java break keyword is used to break the loop or switch statement. It breaks the current flow of the program at specified conditions.
4. Byte:
Java byte keyword is used to declare a variable that can hold 8-bit data values.
5. Case:
Java case keyword is used with the switch statements to mark blocks of text.
6. Catch:
The Java catch keyword is used to catch the exceptions generated by try statements. It must be used after the try block only.
7. Char:
Java char keyword is used to declare a variable that can hold unsigned 16-bit Unicode characters
8. Class:
Java class keyword is used to declare a class.
9. Continue:
Java continue keyword is used to continue the loop. It continues the current flow of the program and skips the remaining code at the specified condition.
10. Default:
Java default keyword is used to specify the default block of code in a switch statement.
11. Do:
Java do keyword is used in the control statement to declare a loop. It can iterate a part of the program several times.
12. Double:
Java double keyword is used to declare a variable that can hold a 64-bit floating-point number.
13. Else:
Java else keyword is used to indicate the alternative branches in an if statement.
14. Enum:
Java enum keyword is used to define a fixed set of constants. Enum constructors are always private or default.
15. Extends:
Java extends keyword is used to indicate that a class is derived from another class or interface.
16. Final:
- Java’s final keyword is used to indicate that a variable holds a constant value. It is used with a variable. It is used to restrict the user from updating the value of the variable.
17. Finally:
: Java finally keyword indicates a block of code in a try-catch structure. This block is always executed whether an exception is handled or not.
18. Float:
Java float keyword is used to declare a variable that can hold a 32-bit floating-point number.
19. For:
Java for keywords is used to start a loop. It is used to execute a set of instructions/functions repeatedly when some condition becomes true. If the number of iterations is fixed, it is recommended to use for loop.
20. If:
: Java if keyword tests the condition. It executes the if block if the condition is true.
21. Implements:
Java implements keyword is used to implement an interface.
22. Import:
: Java import keyword makes classes and interfaces available and accessible to the current source code.
23. Instance of:
Java instance of keyword is used to test whether the object is an instance of the specified class or implements an interface.
24. Int:
Java int keyword is used to declare a variable that can hold a 32-bit signed integer.
25. Interface:
Java interface keyword is used to declare an interface. It can have only abstract methods.
26. Long:
Java long keyword is used to declare a variable that can hold a 64-bit integer.
27. Native:
Java native keyword is used to specify that a method is implemented in native code using JNI (Java Native Interface).
28. New:
Java’s new keyword is used to create new objects.
29. Null:
Java null keyword is used to indicate that a reference does not refer to anything. It removes the garbage value.
30. Package:
: Java package keyword is used to declare a Java package that includes the classes.
31. Private:
Java private keyword is an access modifier. It is used to indicate that a method or variable may be accessed only in the class in which it is declared.
32. Protected:
The java-protected keyword is an access modifier. It can be accessible within the package and outside the package but through inheritance only. It can’t be applied to the class.
33. Public:
Java public keyword is an access modifier. It is used to indicate that an item is accessible anywhere. It has the widest scope among all other modifiers.
34. Return:
Java return keyword is used to return from a method when its execution is complete.
35. Short:
Java short keyword is used to declare a variable that can hold a 16-bit integer.
36. Static:
Java static keyword is used to indicate that a variable or method is a class method. The static keyword in Java is mainly used for memory management.
37. Strictfp:
Java strictfp is used to restrict the floating-point calculations to ensure portability.
38. Super:
Java super keyword is a reference variable that is used to refer to parent class objects. It can be used to invoke the immediate parent class method.
39. Switch:
The Java switch keyword contains a switch statement that executes code based on test value. The switch statement tests the equality of a variable against multiple values.
40. Synchronized:
Java synchronized keyword is used to specify the critical sections or methods in multithreaded code.
41. This:
: Java this keyword can be used to refer to the current object in a method or constructor.
42. Throw:
The Java throw keyword is used to explicitly throw an exception. The throw keyword is mainly used to throw custom exceptions. It is followed by an instance.
43. Throws:
The Java throws keyword is used to declare an exception. Checked exceptions can be propagated with throws.
44. Transient:
Java transient keyword is used in serialization. If you define any data member as transient, it will not be serialized.
45. Try:
: Java try keyword is used to start a block of code that will be tested for exceptions. The try block must be followed by either catch or a final block.
46. Void:
Java void keyword is used to specify that a method does not have a return value.
47. Volatile:
Java volatile keyword is used to indicate that a variable may change asynchronously.
48. While:
Java while keyword is used to start a while loop. This loop iterates a part of the program several times. If the number of iterations is not fixed, it is recommended to use the while loop.