Yandex

Getting StartedGetting Started6
❯

  1. 1Introduction to Java
  2. 2Install Java on Linux
  3. 3Install Java on Windows 10
  4. 4Install Java on Windows 11
  5. 5Install Java on macOS
  6. 6Java Hello World Program

Java BasicsJava Basics7
❯

  1. 1Java Comments
  2. 2Java Variables
  3. 3Java Literals Explained - Types & Examples
  4. 4Java Data Types
  5. 5Java Operators
  6. 6Java Operator Precedence
  7. 7Java Basic Input and Output

Java Conditional StatementsJava Conditional Statements6
❯

  1. 1Java Conditional Statements
  2. 2Java If Statement
  3. 3Java if-else Statement
  4. 4Java if-else-if Statement
  5. 5Java Switch Statement
  6. 6Java Ternary Operator

Java LoopsJava Loops7
❯

  1. 1Java Loops
  2. 2Java For Loop
  3. 3Java For-Each Loop
  4. 4Java While Loop
  5. 5Java Do-While Loop
  6. 6Java break Statement
  7. 7Java Continue Statement

Java OOP ConceptsJava OOP Concepts23
❯

  1. 1Java OOP Introduction
  2. 2Java Class
  3. 3Java Class Constructor
  4. 4Java Class Objects
  5. 5Java Access Modifiers
  6. 6Java Static Variables in Classes
  7. 7Java Static Methods Explained
  8. 8Java Static Blocks
  9. 9Java final Variables
  10. 10Java final Methods
  11. 11Java final class
  12. 12Inheritance in Java
  13. 13Java Method Overriding
  14. 14Java Abstraction in OOP
  15. 15Interfaces in Java
  16. 16Polymorphism in Java
  17. 17Encapsulation in Java
  18. 18Java Nested Classes
  19. 19Java Nested Static Class
  20. 20Java Anonymous Class
  21. 21Java Singleton Class
  22. 22Java Enums
  23. 23Reflection in Java

Java ReferenceJava Reference6
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  1. 1Java Exceptions
  2. 2Java Keywords
  3. 52Java String Methods - Syntax and Description
  4. 92Java ArrayList Methods - Complete Reference with Syntax and Description
  5. 93Java LinkedList Methods - Complete Reference with Syntax and Description
  6. 94Java HashMap Methods - Syntax and Descriptions

Java Exceptions and Their HandlingJava Exceptions and Their Handling3
❯

  1. 1Java try-catch
  2. 2Java catch Multiple Exceptions
  3. 3Java try-with-resources

Java Advanced ConceptsJava Advanced Concepts3
❯

  1. 1Java Annotations
  2. 2Java Logging
  3. 3Java Assertions

ProgramGuru

Java HashMap Methods Reference

clear()
public void clear()
Removes all mappings from the map.
clone()
public Object clone()
Returns a shallow copy of the HashMap.
compute()
public V compute(K key, BiFunction remappingFunction)
Attempts to compute a new mapping for the specified key.
computeIfAbsent()
public V computeIfAbsent(K key, Function mappingFunction)
Computes and stores a value for the key if it is not already present.
computeIfPresent()
public V computeIfPresent(K key, BiFunction remappingFunction)
Updates the value only if the key is already present.
containsKey()
public boolean containsKey(Object key)
Checks if the map contains the specified key.
containsValue()
public boolean containsValue(Object value)
Checks if the map maps one or more keys to the specified value.
entrySet()
public Set> entrySet()
Returns a set view of the key-value mappings.
forEach()
public void forEach(BiConsumer action)
Performs an action for each entry in the map.
get()
public V get(Object key)
Returns the value to which the specified key is mapped, or null.
getOrDefault()
public V getOrDefault(Object key, V defaultValue)
Returns the value for the key, or a default if the key is not present.
isEmpty()
public boolean isEmpty()
Checks if the map contains no key-value mappings.
keySet()
public Set keySet()
Returns a Set view of the keys contained in the map.
merge()
public V merge(K key, V value, BiFunction remappingFunction)
Merges the value with existing value using a mapping function.
put()
public V put(K key, V value)
Associates the specified value with the specified key in the map.
putAll()
public void putAll(Map m)
Copies all of the mappings from the specified map to this map.
putIfAbsent()
public V putIfAbsent(K key, V value)
Puts the value only if the key is not already associated with a value.
remove()
public V remove(Object key)public boolean remove(Object key, Object value)
Removes the mapping for the specified key or key-value pair.
replace()
public V replace(K key, V value)public boolean replace(K key, V oldValue, V newValue)
Replaces the entry for the specified key if it is currently mapped.
replaceAll()
public void replaceAll(BiFunction function)
Replaces each entry’s value using the provided function.
size()
public int size()
Returns the number of key-value mappings in the map.
values()
public Collection values()
Returns a Collection view of the values contained in the map.

Java Reference❯

  1. 1Java Exceptions
  2. 2Java Keywords
  3. 3Java abstract Keyword
  4. 4Java assert Keyword
  5. 5Java boolean Keyword
  6. 6Java break Keyword
  7. 7Java byte Keyword
  8. 8Java case Keyword
  9. 9Java catch Keyword
  10. 10Java char Keyword
  11. 11Java class Keyword
  12. 12Java const Keyword
  13. 13Java continue Keyword
  14. 14Java default Keyword
  15. 15Java do Keyword
  16. 16Java double Keyword
  17. 17Java else Keyword
  18. 18Java enum Keyword
  19. 19Java extends Keyword
  20. 20Java final Keyword
  21. 21Java finally Keyword
  22. 22Java float Keyword
  23. 23Java for Keyword
  24. 24Java goto Keyword
  25. 25Java if Keyword
  26. 26Java implements Keyword
  27. 27Java import Keyword
  28. 28Java instanceof Keyword
  29. 29Java int Keyword
  30. 30Java interface Keyword
  31. 31Java long Keyword
  32. 32Java native Keyword
  33. 33Java new Keyword
  34. 34Java null Keyword
  35. 35Java package Keyword
  36. 36Java private Keyword
  37. 37Java protected Keyword
  38. 38Java public Keyword
  39. 39Java return Keyword
  40. 40Java short Keyword
  41. 41Java static Keyword
  42. 42Java strictfp Keyword
  43. 43Java super Keyword
  44. 44Java switch Keyword
  45. 45Java synchronized Keyword
  46. 46Java this Keyword
  47. 47Java transient Keyword
  48. 48Java try Keyword
  49. 49Java void Keyword
  50. 50Java volatile Keyword
  51. 51Java while Keyword
  52. 52Java String Methods - Syntax and Description
  53. 53Java String charAt() method
  54. 54Java String codePointAt() method
  55. 55Java String codePointBefore() method
  56. 56Java String codePointCount() method
  57. 57Java String compareTo() method
  58. 58Java String compareToIgnoreCase() method
  59. 59Java String concat() method
  60. 60Java String contains() method
  61. 61Java String contentEquals() method
  62. 62Java String copyValueOf() method
  63. 63Java String endsWith() method
  64. 64Java String equals() method
  65. 65Java String equalsIgnoreCase() method
  66. 66Java String format() method
  67. 67Java String getBytes() method
  68. 68Java String getChars() method
  69. 69Java String hashCode() method
  70. 70Java String indexOf() method
  71. 71Java String intern() method
  72. 72Java String isEmpty() method
  73. 73Java String join() method
  74. 74Java String lastIndexOf() method
  75. 75Java String length() method
  76. 76Java String matches() method
  77. 77Java String offsetByCodePoints() method
  78. 78Java String regionMatches() method
  79. 79Java String replace() method
  80. 80Java String replaceAll() method
  81. 81Java String replaceFirst() method
  82. 82Java String split() method
  83. 83Java String startsWith() method
  84. 84Java String subSequence() method
  85. 85Java String substring() method
  86. 86Java String toCharArray() method
  87. 87Java String toLowerCase() method
  88. 88Java String toString() method
  89. 89Java String toUpperCase() method
  90. 90Java String trim() method
  91. 91Java String valueOf() method
  92. 92Java ArrayList Methods - Complete Reference with Syntax and Description
  93. 93Java LinkedList Methods - Complete Reference with Syntax and Description
  94. 94Java HashMap Methods - Syntax and Descriptions

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