|
| 1 | +### Java Keywords |
| 2 | + |
| 3 | +-------- |
| 4 | + |
| 5 | +Java keywords are also known as reserved words. Keywords are particular words which acts as a key to a code. These are predefined words by Java so it cannot be used as a variable or object name. |
| 6 | + |
| 7 | +##### List of Java Keywords |
| 8 | + |
| 9 | +A list of Java keywords or reserved words are given below: |
| 10 | + |
| 11 | + 1- abstract: Java abstract keyword is used to declare abstract class. Abstract class can provide the implementation of interface. It can have abstract and non-abstract methods. |
| 12 | + |
| 13 | + 2- boolean: Java boolean keyword is used to declare a variable as a boolean type. It can hold True and False values only. |
| 14 | + |
| 15 | + 3- break: Java break keyword is used to break loop or switch statement. It breaks the current flow of the program at specified condition. |
| 16 | + |
| 17 | + 4- byte: Java byte keyword is used to declare a variable that can hold an 8-bit data values. |
| 18 | + |
| 19 | + 5- case: Java case keyword is used to with the switch statements to mark blocks of text. |
| 20 | + |
| 21 | + 6- catch: Java catch keyword is used to catch the exceptions generated by try statements. It must be used after the try block only. |
| 22 | + |
| 23 | + 7- char: Java char keyword is used to declare a variable that can hold unsigned 16-bit Unicode characters |
| 24 | + |
| 25 | + 8- class: Java class keyword is used to declare a class. |
| 26 | + |
| 27 | + 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. |
| 28 | + |
| 29 | + 10- default: Java default keyword is used to specify the default block of code in a switch statement. |
| 30 | + |
| 31 | + 11- do: Java do keyword is used in control statement to declare a loop. It can iterate a part of the program several times. |
| 32 | + |
| 33 | + 12- double: Java double keyword is used to declare a variable that can hold a 64-bit floating-point numbers. |
| 34 | + |
| 35 | + 13- else: Java else keyword is used to indicate the alternative branches in an if statement. |
| 36 | + |
| 37 | + 14- enum: Java enum keyword is used to define a fixed set of constants. Enum constructors are always private or default. |
| 38 | + |
| 39 | + 15- extends: Java extends keyword is used to indicate that a class is derived from another class or interface. |
| 40 | + |
| 41 | + 16- final: Java final keyword is used to indicate that a variable holds a constant value. It is applied with a variable. It is used to restrict the user. |
| 42 | + |
| 43 | + 17- finally: Java finally keyword indicates a block of code in a try-catch structure. This block is always executed whether exception is handled or not. |
| 44 | + |
| 45 | + 18- float: Java float keyword is used to declare a variable that can hold a 32-bit floating-point number. |
| 46 | + |
| 47 | + 19- for: Java for keyword is used to start a for loop. It is used to execute a set of instructions/functions repeatedly when some conditions become true. If the number of iteration is fixed, it is recommended to use for loop. |
| 48 | + |
| 49 | + 20- if: Java if keyword tests the condition. It executes the if block if condition is true. |
| 50 | + |
| 51 | + 21- implements: Java implements keyword is used to implement an interface. |
| 52 | + |
| 53 | + 22- import: Java import keyword makes classes and interfaces available and accessible to the current source code. |
| 54 | + |
| 55 | + 23- instanceof: Java instanceof keyword is used to test whether the object is an instance of the specified class or implements an interface. |
| 56 | + |
| 57 | + 24- int: Java int keyword is used to declare a variable that can hold a 32-bit signed integer. |
| 58 | + |
| 59 | + 25- interface: Java interface keyword is used to declare an interface. It can have only abstract methods. |
| 60 | + |
| 61 | + 26- long: Java long keyword is used to declare a variable that can hold a 64-bit integer. |
| 62 | + |
| 63 | + 27- native: Java native keyword is used to specify that a method is implemented in native code using JNI (Java Native Interface). |
| 64 | + |
| 65 | + 28- new: Java new keyword is used to create new objects. |
| 66 | + |
| 67 | + 29- null: Java null keyword is used to indicate that a reference does not refer to anything. It removes the garbage value. |
| 68 | + |
| 69 | + 30- package: Java package keyword is used to declare a Java package that includes the classes. |
| 70 | + |
| 71 | + 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. |
| 72 | + |
| 73 | + 32- protected: Java protected keyword is an access modifier. It can be accessible within package and outside the package but through inheritance only. It can't be applied on the class. |
| 74 | + |
| 75 | + 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. |
| 76 | + |
| 77 | + 34- return: Java return keyword is used to return from a method when its execution is complete. |
| 78 | + |
| 79 | + 35- short: Java short keyword is used to declare a variable that can hold a 16-bit integer. |
| 80 | + |
| 81 | + 36- static: Java static keyword is used to indicate that a variable or method is a class method. The static keyword in Java is used for memory management mainly. |
| 82 | + |
| 83 | + 37- strictfp: Java strictfp is used to restrict the floating-point calculations to ensure portability. |
| 84 | + |
| 85 | + 38- super: Java super keyword is a reference variable that is used to refer parent class object. It can be used to invoke immediate parent class method. |
| 86 | + |
| 87 | + 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. |
| 88 | + |
| 89 | + 40- synchronized: Java synchronized keyword is used to specify the critical sections or methods in multithreaded code. |
| 90 | + |
| 91 | + 41- this: Java this keyword can be used to refer the current object in a method or constructor. |
| 92 | + |
| 93 | + 42- throw: The Java throw keyword is used to explicitly throw an exception. The throw keyword is mainly used to throw custom exception. It is followed by an instance. |
| 94 | + |
| 95 | + 43- throws: The Java throws keyword is used to declare an exception. Checked exception can be propagated with throws. |
| 96 | + |
| 97 | + 44- transient: Java transient keyword is used in serialization. If you define any data member as transient, it will not be serialized. |
| 98 | + |
| 99 | + 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 finally block. |
| 100 | + |
| 101 | + 46- void: Java void keyword is used to specify that a method does not have a return value. |
| 102 | + |
| 103 | + 47- volatile: Java volatile keyword is used to indicate that a variable may change asynchronously. |
| 104 | + |
| 105 | + 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 iteration is not fixed, it is recommended to use while loop. |
| 106 | + |
| 107 | + |
0 commit comments