Skip to main content

100 Java Questions

core java interview questions


  1. WHAT IS  JAVA ?
  2. The Java Platform?
  3. what is Unicode?
  4. what is Byte code?
  5. who developed the java?
  6. when java is invented?
  7. what is the advantage of java?
  8. what is oops concept in java ??
  9. WHERE IT AS USE?
  10. WHY JAVA USE? 
  11. what is the use of oops?
  12. why java intermediate language?
  13. what are the dis advantage of oops?
  14.  how many java language keywords?
  15. what is the use of keywords?
  16. why we are using java keywords?
  17. what are the use of data types?
  18. how many  data types are supported in java?
  19. how many numeric data types are supported in java?
  20. java control structures?
  21. what is break?
  22. what is continue in java loop?
  23. java control  statements ? 
  24. java Control loops?
  25. how to declare the variable in java?
  26. what is array ?
  27. how to initialize array in java?
  28. how many types of arrays in java ?
  29. what is the use of array?
  30. array index out of bounds exception java?
  31. how to  Accessing Array Element?
  32. how to  manipulation and replacement in array?
  33. how to calculate the array length in java?
  34. what is the class and it's syntax?
  35. what is const/
  36. what is default?
  37. what is the object?
  38. how to create object in java?
  39. how to create object in java without new operator?
  40. what is the interface in java?
  41. what is the method  and it's syntax?
  42. java variables?
  43. what is class variable/
  44. what is instance variables?
  45. what is array component variable ?
  46. what is method  Parameter Variable?
  47. what is Exception Handler Parameter Variable?
  48. what is Local Variable?
  49. what is the static variable in java?
  50. what is static class in java?
  51. what is public static  in java?
  52. what is private static in java?
  53. what is static block in java ?
  54. what is difference public static and private static ?
  55. how many types of errors in java?
  56.   what is static constructor ?
  57. what is static constructor?
  58. what is the static object in java?
  59.  what is static polymorphism/
  60. what is method overloading?
  61. what is method overriding in java?
  62. what is method prototype in java?
  63. what is method binding in java/
  64. call by method in java?
  65. what are pass by reference and pass by value in java/
  66. what is the hashmap and map?
  67. java constructors?
  68. java destructor ?
  69. what is final keywords in java?
  70. what is final method in java/
  71. what is final class in java?
  72. what is the supper key word in java?
  73. what is  abstract method in java
  74. what is assert in java?
  75. what is void in java?
  76. what is the difference b/w the  implements and extends ?
  77. what is else?
  78.  inheritance in java?
  79. how many type inheritance in java?
  80. what is this  in java?
  81. why java does not support  multiple inheritance in java?
  82. exception handling in java ?
  83. What happens when an Exception occurs?
  84. what is arithmetic exception ?
  85. what is environmental exception in java?
  86. what is undetectable exception in java?
  87. Benefits of Exception Handling framework
  88. Catching exceptions with try-catch
  89. Catching exceptions with finally
  90. Throwing exceptions
  91. Rules in exception handling
  92. Exception class hierarchy
  93. Checked exception and unchecked exception
  94. Creating your own exception class
  95. what is the palymorphism in java?
  96. what is the difference b/w interface and abstract class?
  97. what is the purpose of garbage collection in java when it is used?
  98. explain different why of using thread/
  99.  d/w hashmap and hash table?
  100. d/w vector and array list?
  101. d/w swing and awt?
  102. difference between constructor and method?
  103. what is iterator?
  104. what is public ,static , private , protected ,default,modifiers,


Labels:

Popular posts from this blog

insert document in collection mongodb

 Insert document in collection Two types of insert Insert single records:  Insert multiple records Insert single records:    syntax:  db.collection.insertOne(    <document>,    {       writeConcern: <document>    } ) Example 1:  db.users.insertOne({"name":"ram","email":"ram@gmail.com"})  Example 2:  db.users.insertOne( [{"employee":{"name":"ram","email":"ram@gmail.com"}}] ) Insert multiple records:   syntax : db.Collection_name.insertMany( [<document 1>, <document 2>, …], {     writeConcern: <document>,     ordered: <boolean> }) Example:  db.users.insertMany([{"name":"ram","email":"ram@gmail.com"},{"name":"raju","email":"raju@gmail.com"}])
Read more

Collection Shell Commands in MongoDB

Create Collection  Syntax: db.createCollection("Collection Name"); Example: db.createCollection("users"); Delete collection in Mongodb Shell Command db.collection.drop()  Find Collection in Mongodb Shell Command db.collection.find() Show all Collection in Mongodb Shell Command show collections Creat Collection in Mongodb Shell Command db.createCollection("users") Rename the Collection In Mongodb Shell Command db.collection.renameCollection()   Update the single document in MongoDB collections Shell Command db.collection.updateOne()  Updates all the documents in MongoDB collections that match the given query.  db.collection.updateMany() Replaces the first matching document in MongoDB collection db.collection.replaceOne()  Deletes the first document in Mongodb collection db.collection.deleteOne()  db.collection.deleteMany()
Read more