The isEmpty() method is used to return true if this map contains no key-value mappings
Following is the declaration for java.util.WeakHashMap.isEmpty() method.
public boolean isEmpty()
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The method call returns true if this map contains no key-value mappings.
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The following example shows the usage of java.util.WeakHashMap.isEmpty() method.
package com.tutorialspoint; import java.util.Map; import java.util.WeakHashMap; public class WeakHashMapDemo { public static void main(String[] args) { Map<String, String> weakHashMap = new WeakHashMap<String, String>(); // check map contents System.out.println("Checking the map entries"); System.out.println("Map is empty: "+weakHashMap.isEmpty()); // put keys and values in the Map System.out.println("Putting values into the Map"); weakHashMap.put("1", "first"); weakHashMap.put("2", "two"); weakHashMap.put("3", "three"); // checking Map System.out.println("Map is empty: "+weakHashMap.isEmpty()); } }
Let us compile and run the above program, this will produce the following result.
Checking the map entries Map is empty: true Putting values into the Map Map is empty: false