The HashTable.contains() method is present in the HashTable class inside the java.util package.
It is used to check whether or not a particular value is being mapped by any keys present in the HashTable.
HashTable.contains(Object value)
HashTable.contains() takes one parameter.
value: The value of the hashtable whose mapping is to be verified.HashTable.contains() returns a boolean value.
true: If the value passed as an argument is being mapped by any keys present in the HashTable.
false: If the value passed as argument is not being mapped by any keys present in the HashTable.
Let’s go over this with the help of an example.
Suppose we have the following HashTable:
{
1 = "Let's",
5 = "see",
2 = "HashTable.contains()",
27 = "method"
}
When we use HashTable.contains(), the method returns true if any of the values present in HashTable are parameterized inside HashTable.contains().
Otherwise, it returns false.
Let’s look at the below code snippet to better understand this.
import java.util.*;class Main{public static void main(String[] args){Hashtable<Integer, String> h1 = new Hashtable<Integer, String>();h1.put(1, "Let's");h1.put(5, "see");h1.put(2, "Hashtable.contains()");h1.put(27, "method");h1.put(9, "in java.");System.out.println("The Hashtable is: " + h1);System.out.println("Is \"HashTable.contains()\" being mapped by any of the keys in the HashTable: " + h1.contains("HashTable.contains()"));System.out.println("Is \"in java. being mapped\" by any of the keys in the HashTable: " + h1.contains("in java."));System.out.println("Is \"value being mapped\" by any of the keys in the HashTable: " + h1.contains("value"));}}
Main class.main function.Hashtable consisting of Integer type keys and String type values.HashTable by using the Hashtable.put() method.HashTable.HashTable with the result and a message.In this way, we can use the HashTable.contains() method to check whether or not a particular value is being mapped by any keys present in the HashTable.