In a programmer’s life, knowing all the keywords are very essential to build a program properly. In this article, we will discuss all the keywords that JDK has in reserve.<\/p>\n
Keywords are special tokens that add a different meaning to the language compiler. Each keyword has its own individual function and performs a specific task assigned to it. In Java, we have 50 such reserved words, out of which 48 are in use, and 2 are reserved but not in use. Keywords cannot be used as identifiers in a program, so a programmer must know all the keywords to avoid any kind of syntax or logical errors.<\/p>\n
Let us study all the keywords that Java provides us with in detail.<\/p>\n
1. abstract:<\/strong> Using the abstract keyword in Java, we can create abstract classes and methods. Abstract keywords are essential to implement abstraction into a program.<\/p>\n Example of abstract in Java:<\/strong><\/p>\n 2. assert:<\/strong> Using the assert keyword, we can implement assertion in a program. Using it we can check the correctness of any assumptions made in a program. The assert keyword was added in JDK 1.4.<\/p>\n Example of assert\u00a0in Java:<\/strong><\/p>\n 3. boolean:<\/strong> Using the boolean keyword, we can declare a boolean variable. A Boolean variable is a variable that has two values, true and false.<\/p>\n Example of boolean in Java:<\/strong><\/p>\n 4. break:<\/strong> The break keyword is a jump statement using which we can use to break out of a loop or switch statement. The break statement terminates the currently executing block of code.<\/p>\n Example of break in Java:<\/strong><\/p>\n 5. byte:<\/strong> Using the byte keyword in Java, we can declare a variable that can hold a value of 1 byte or 8 bit.<\/p>\n Example of byte in Java:<\/strong><\/p>\n 6. case:<\/strong> Using the case statement, we can declare each case inside a switch-case block. case keyword is used to give multiple conditions to switch statements. This is used in a switch case statement. It contains the statements, which are executed when the value in the case matches a condition.<\/p>\n Example of case in Java:<\/strong><\/p>\n 7. catch:<\/strong> The catch keyword is part of exception handling in Java. Using the catch keyword, we can catch or capture the error caught by the try block. A catch block can exist only after the try block.<\/p>\n Example of catch in Java:<\/strong><\/p>\n 8. char:<\/strong> Using the char keyword, we can declare a character variable.<\/p>\n Example of char\u00a0in Java:<\/strong><\/p>\n 9. class: <\/strong> The class keyword in Java is used to declare Java classes. It usually contains the methods and variables, which are the attributes of the object.<\/p>\n Example of class in Java:<\/strong><\/p>\n 10. continue:<\/strong> Continue is also a jump statement in Java. Using it, we can terminate the current iteration and continue from the next iteration inside the loop.<\/p>\n Example of continue in Java:<\/strong><\/p>\n 11. default:<\/strong> default is the keyword using which we can declare the default statement inside a switch case. It is executed when none of the cases match.<\/p>\n Example of default in Java:<\/strong><\/p>\n 12. do:<\/strong> Using the do keyword, we can declare a do-while loop. It is an exit-controlled loop, so it doesn\u2019t have any entry condition.<\/p>\n Example of do in Java:<\/strong><\/p>\n 13. double:<\/strong> Using the double keyword, we can declare a double variable. A double variable can hold a 64bit long floating point number.<\/p>\n Example of double in Java:<\/strong><\/p>\n 14. else:<\/strong> Using the else keyword, we can write statements that will be executed when the if block doesn\u2019t execute successfully.<\/p>\n Example of else in Java:<\/strong><\/p>\n 15. enum:<\/strong> Using the enum keyword, we can declare an enumerated class. It consists of a fixed set of constants. Enum constructors are always private by default. The enum keyword was added to Java in JDK 5.0.<\/p>\n Example of enum in Java:<\/strong><\/p>\n 16. extends:<\/strong> The extends keyword is used in inheritance. Using it we can inherit one class into another.<\/p>\n Example of extends in Java:<\/strong><\/p>\n 17. final:<\/strong> Using the final keyword, we can finalize the value of a variable. It means that the value cannot be updated by the user whatsoever.<\/p>\n Example of final in Java:<\/strong><\/p>\n 18. finally:<\/strong> The finally keyword is used after the try-catch block. It indicates the end of the block. Unlike the try-catch block, the finally block will be executed regardless of whether an exception is found or not.<\/p>\n Example of finally in Java:<\/strong><\/p>\n 19. float:<\/strong> Using the float keyword, we can declare a float variable in Java. Thus, the float variable holds a 32-bit long floating-point number.<\/p>\n Example of float in Java:<\/strong><\/p>\n 20. for:<\/strong> Using the for keyword, we can declare a for loop. It is an entry-controlled loop; for this kind of loop, the number of iterations should be known beforehand.<\/p>\n Example of for in Java:<\/strong><\/p>\n 21. if:<\/strong> In Java, the if keyword is used to declare an if conditional statement. Therefore, the if statement is used to check the viability of a condition.<\/p>\n Example of if\u00a0in Java:<\/strong><\/p>\n 22. implements:<\/strong> Using the implements keyword in Java, we can declare an interface. However, it is like the inheritance extends keyword; here, to access an interface, we have to use the implements keyword.<\/p>\n Example of implements in Java:<\/strong><\/p>\n 23. import:<\/strong> Using the import keyword in Java, we can access classes and interfaces present inside a package in the current code.<\/p>\n Example of import in Java:<\/strong><\/p>\n 24. instanceof:<\/strong> Using the instanceof keyword in Java, we can check whether a given object is an instance of another class or not. Hence It returns true if the given object is an instance and false if not.<\/p>\n Example of instanceof in Java:<\/strong><\/p>\n 25. int:<\/strong> Using the int keyword, we can declare a variable of integer datatype. Therefore, it can hold a value of 32-bit long.<\/p>\n Example of int in Java:<\/strong><\/p>\n 26. interface:<\/strong> Using the interface keyword in Java, we can declare an interface inside the code.<\/p>\n Example of interface in Java:<\/strong><\/p>\n 27. long:<\/strong> Using the long keyword, we can declare variables with the long data type. Therefore, the long data type is an integer that can hold 64 bits of data.<\/p>\n Example of long in Java:<\/strong><\/p>\n 28. native:<\/strong> The native keyword in Java is used to indicate that a method is implemented in native code using JNI[Java Native Interface].<\/p>\n Example of native in Java:<\/strong><\/p>\n 29. new:<\/strong> Using the new keyword, we can create a new instance of a class.<\/p>\n Example of new in Java:<\/strong><\/p>\n 30. Package:<\/strong> Using the package keyword in Java, we can create a new package in the Java library.<\/p>\n Example of Package in Java:<\/strong><\/p>\n 31. private:<\/strong> The private keyword is an access modifier that declares a class or method as private; i.e, it can only be accessed by its local variables.<\/p>\n Example of private in Java:<\/strong><\/p>\n 32. protected:<\/strong> protected is also an access modifier that declares a class or method as protected; i.e, it can be accessed by files in the PWD(Present Working Directory).<\/p>\n Example of protected in Java:<\/strong><\/p>\n 33. public:<\/strong> public is another access modifier that declares a class or method as public; i,e; it can be accessed globally.<\/p>\n Example of public in Java:<\/strong><\/p>\n 34. return:<\/strong> The return keyword is used inside a method when it is required to return a value of a certain return type, except void.<\/p>\n Example of return in Java:<\/strong><\/p>\n 35. short:<\/strong> In Java, the short keyword declares variables that can hold an integer value of 16 bits.<\/p>\n Example of short in Java:<\/strong><\/p>\n 36. static:<\/strong> In Java, the static keyword declares a static variable or method. Hence, A static variable or method is stored in a static memory location.<\/p>\n Example of static in Java:<\/strong><\/p>\n 37. strictfp:<\/strong> In Java, the strictfp keyword ensures that every platform gets the same result for floating-point operations. The strictfp keyword is used on classes, methods, and interfaces. However, this keyword was introduced in JDK 1.2.<\/p>\n Example of strictfp in Java:<\/strong><\/p>\n 38. super:<\/strong> The super keyword distinguishes variables with the same name in both the parent class and child class in inheritance.<\/p>\n Example of super in Java:<\/strong><\/p>\n 39. switch:<\/strong> Using the switch keyword, we can initiate the switch case block in Java code.<\/p>\n Example of switch in Java:<\/strong><\/p>\n 40. synchronized:<\/strong> Using the synchronized keyword in Java, we can specify the critical section to be executed during multithreaded coding.<\/p>\n Example of synchronized keyword in Java:<\/strong><\/p>\n 41. this:<\/strong> this keyword in Java is used to distinguish local variables from global variables.<\/p>\n Example of this in Java:<\/strong><\/p>\n 42. throw:<\/strong> The throw keyword in Java is used to throw custom-made exceptions explicitly into the code.<\/p>\n Example of void in Java:<\/strong><\/p>\n 43. throws:<\/strong> The throws keyword is used to propagate a checked exception.<\/p>\n Example of throws in Java:<\/strong><\/p>\n 44. transient:<\/strong> Using the transient keyword in Java, we can deserialize a variable. Therefore, when a variable is declared transient, it is not considered for serialization.<\/p>\n Example of a transient in Java:<\/strong><\/p>\n 45. try:<\/strong> The try block is used in exception handling to test a block of code for exceptions. Therefore, the try block is always followed by a catch block or finally block.<\/p>\n Example of try in Java:<\/strong><\/p>\n 46. void:<\/strong> Using the void keyword, we can declare that the method will not return any value.<\/p>\n Example of void in Java:<\/strong><\/p>\n 47. volatile:<\/strong> The volatile keyword in Java is used to indicate that a variable can change asynchronously.<\/p>\n Example of volatile in Java:<\/strong><\/p>\n 48. while:<\/strong> Using the While keyword, we can declare a while loop. A while loop is an entry-controlled loop, where the number of iterations is not fixed.<\/p>\n Example of while in Java:<\/strong><\/p>\n Note:<\/strong> Two other keywords are reserved but not used: const<\/strong> and goto.<\/strong> Words like true, false, and null might seem like keywords, but they are actually literals.<\/p>\n While memorising all Java keywords can seem daunting at first, there are effective strategies to aid your learning process. Here are some tips to consider:<\/p>\n In this article, we took a brief look at all the keywords that are present in Java. However, each of these keywords has a vast role in coding. Knowing each keyword in detail is essential for every programmer.<\/p>\n","protected":false},"excerpt":{"rendered":" In a programmer’s life, knowing all the keywords are very essential to build a program properly. In this article, we will discuss all the keywords that JDK has in reserve. What are Keywords in...<\/p>\n","protected":false},"author":5,"featured_media":108894,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[32],"tags":[4164,7473,7474,7475,7476,7477,7570,8324,15806],"class_list":["post-15422","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-java","tag-enum","tag-java-enum","tag-java-enum-constructor","tag-java-enum-example","tag-java-enum-methods","tag-java-enum-valueof","tag-java-keyword-list","tag-list-of-abstract-data-types","tag-what-is-keyword-in-java"],"yoast_head":"\nabstract class DataFlair\r\n<\/pre>\n
int i = 10;\r\n assert i > 5 : \"The value is greater than 5\";\r\n<\/pre>\n
boolean flag = true;\r\n<\/pre>\n
i=0;\r\nwhile(true)\r\n{\r\n if(i==10)\r\n break;\r\n i++;\r\n}\r\n<\/pre>\nbyte num=1;\r\n<\/pre>\n
{\r\n case 1:\r\n System.out.println(\u201cONE\u201d);\r\n break;\r\n}\r\n<\/pre>\ncatch (Exception e)\r\n{\r\n System.out.println(\u201cAn exception was caught by the try block\u201d);\r\n}\r\n<\/pre>\nchar ch=\u2019A\u2019;\r\n<\/pre>\n
class DataFlair\r\n<\/pre>\n
i=0;\r\nwhile(i<=10)\r\n{\r\n if(i==5)\r\n continue;\r\n i++;\r\n}\r\n<\/pre>\nSwitch(num)\r\n{\r\n case 1:\r\n System.out.println(\u201cONE\u201d);\r\n break;\r\n default:\r\n System.out.println(\u201cNot ONE\u201d);\r\n}\r\n<\/pre>\ni=0;\r\ndo{\r\n i++;\r\n }while(i<=10);\r\n<\/pre>\ndouble d= 1.23456;\r\n<\/pre>\n
i=5;\r\nif(i!=5)\r\nSystem.out.println(\u201cNot Five\u201d);\r\nelse\r\nSystem.out.println(\u201cFIVE\u201d);\r\n<\/pre>\n
enum Rainbow\r\n{\r\n Violet, Indigo, Blue, Green,\r\n Yellow, Orange, Red;\r\n}\r\n<\/pre>\nclass subclass extends superclass\r\n<\/pre>\n
final int num = 1000; \r\n<\/pre>\n
finally{\r\nSystem.out.println(\"This block is always executed whatsoever!\");\r\n} \r\n<\/pre>\nfloat num= 1.324f;\r\n<\/pre>\n
for(i=0;i<10;i++)\r\n{\r\n System.out.println(i);\r\n}\r\n<\/pre>\ni=5;\r\nif(i==5)\r\n{\r\n System.out.println(\u201cThe Number is Five\u201d);\r\n}\r\n<\/pre>\ninterface DataFlair{\r\npublic void intern();\r\n}\r\nclass internship implements DataFlair\r\n{\r\n Public void intern()\r\n {\r\n System.out.println(\u201cInternship Granted\u201d);\r\n }\r\n}\r\n\r\n<\/pre>\nimport java.util.Arrays; \r\n<\/pre>\n
public class DataFlair {\r\n public static void main(String[] args) {\r\n DataFlair Obj1 = new DataFlair();\r\n System.out.println(Obj1 instanceof DataFlair);\/\/ It will return True.\r\n }\r\n}\r\n<\/pre>\nint num=100;\r\n<\/pre>\n
interface DataFlair{}\r\n<\/pre>\nlong num=100000;\r\n<\/pre>\n
Public native void DataFlair();\r\n<\/pre>\n
public class DataFlair {\r\n public static void main(String[] args) {\r\n DataFlair Obj1 = new DataFlair();\r\n}\r\n<\/pre>\npackage com.DataFlair.Keywords;\r\n<\/pre>\n
private class DataFlair{}\r\n<\/pre>\nprotected class DataFlair{}\r\n<\/pre>\npublic class DataFlair{}\r\n<\/pre>\nint sum(int a, int b)\r\n{\r\n return (a+b);\r\n}\r\n \r\n<\/pre>\nshort num=1;\r\n<\/pre>\n
public static void main() \r\n<\/pre>\n
strictfp class DataFlair{}\r\n<\/pre>\nclass DataFlair\r\n{\r\n String name=\u201dCompany\u201d;\r\n}\r\nclass internship extends DataFlair\/\r\n{\r\n String name=\u201dIntern\u201d;\r\n System.out.println(name);\/\/Intern will be printed\r\n System.out.println(super.name);\/\/Company will be printed\r\n}\r\n<\/pre>\nSwitch(num)\r\n{\r\n case 1:\r\n System.out.println(\u201cONE\u201d);\r\n break;\r\n default:\r\n System.out.println(\u201cNot ONE\u201d);\r\n}\r\n<\/pre>\nsynchronized void print(int num)<\/pre>\n
class DataFlair{\r\nString name;\r\nDataFlair(String name)\r\n{\r\n this.name=name;\r\n}\r\n}\r\n\r\n<\/pre>\nthrow new IOException(\"The Input is Not Acceptable\u201d); \r\n \r\n<\/pre>\n
import java.io.*; \r\nclass DataFlair{ \r\n void internship()throws IOException{ \r\n throw new IOException(\"Internship Not Found\"); \r\n } \r\n} \r\n<\/pre>\ntransient int num;\r\n<\/pre>\n
try{\r\n\/\/statement\r\n}catch(exception e){}\r\n\r\n<\/pre>\nvoid main()\r\n<\/pre>\n
static volatile int num=100;\r\n<\/pre>\n
i=5;\r\nwhile(i<=10)\r\n{\r\n i++;\r\n}\r\n<\/pre>\nLearning and Remembering Keywords in Java<\/h3>\n
\n
Conclusion<\/h3>\n