Package com.vaadin.client.flow.collection

Class JsMap<K,V>

java.lang.Object
com.vaadin.client.flow.collection.JsMap<K,V>
Type Parameters:
K - the key type
V - the value type
Direct Known Subclasses:
JreJsMap
@JsType(isNative=true, name="Map", namespace="<global>") public class JsMap<K,V> extends Object
Native JS Map interface with an alternative implementation for JRE usage. Use JsCollections.map() to create an appropriate instance.
Since:
1.0
Author:
Vaadin Ltd

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static interface 
    JsMap.ForEachCallback<K,V>
    Functional interface for iterating all the entries in a JsMap.

  • Constructor Summary

    Constructors
    Constructor
    Description
    JsMap()
    Creates a new instance.

  • Method Summary

    Modifier and Type
    Method
    Description
    void
    clear()
    Removes all mappings from this map.
    boolean
    delete(K key)
    Removes the mapping for a given key.
    void
    forEach(JsMap.ForEachCallback<K,V> callback)
    Invokes the provided callback for each mapping in this map.
    V
    get(K key)
    Gets the value mapped for the given key.
    boolean
    has(K key)
    Checks whether this map contains a mapping for the given key.
    final boolean
    isEmpty()
    Checks if the map is empty (size == 0).
    final JsArray<V>
    mapValues()
    Returns an array of the values in this JsMap.
    JsMap<K,V>
    set(K key, V value)
    Sets a value in this map, overwriting any previous mapping if present.
    int
    size()
    Gets the number of entries in this map.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • JsMap

      public JsMap()
      Creates a new instance.

  • Method Details

    • set

      public JsMap<K,V> set(K key, V value)
      Sets a value in this map, overwriting any previous mapping if present.
      Parameters:
      key - the key to set
      value - the value to set
      Returns:
      this map, for chaining.

    • get

      public V get(K key)
      Gets the value mapped for the given key. Returns null if there is no mapping or if the key is explicitly mapped to null.
      Parameters:
      key - the key to get a value for
      Returns:
      the value corresponding to the given key; or null there is no mapping.

    • has

      public boolean has(K key)
      Checks whether this map contains a mapping for the given key.
      Parameters:
      key - the key to check
      Returns:
      true if there is a mapping for the key; false if there is no mapping

    • delete

      public boolean delete(K key)
      Removes the mapping for a given key.
      Parameters:
      key - the key for which to remove the mapping
      Returns:
      true if the map contained a mapping for the given key prior to calling this method; false if no mapping was present

    • clear

      public void clear()
      Removes all mappings from this map.

    • forEach

      public void forEach(JsMap.ForEachCallback<K,V> callback)
      Invokes the provided callback for each mapping in this map.

      Note that this is the only way of iteration supported in IE11.

      Parameters:
      callback - the callback to invoke for each mapping

    • size

      @JsProperty(name="size") public int size()
      Gets the number of entries in this map.
      Returns:
      the entry count

    • isEmpty

      @JsOverlay public final boolean isEmpty()
      Checks if the map is empty (size == 0).
      Returns:
      true if the map is empty, false otherwise

    • mapValues

      @JsOverlay public final JsArray<V> mapValues()
      Returns an array of the values in this JsMap.
      Returns:
      an array of the values in the map