SimpleBindings containsKey() method in Java with Examples

Last Updated : 15 Feb, 2020

The containsKey() method of SimpleBindings class is used to return true if this map which is backing this SimpleBindings object contains a mapping for the specified key. If SimpleBindings object contains this key then the method returns true else false.

Syntax:

public boolean containsKey(Object key)

Parameters: This method accepts only one parameters key which is key whose presence in this map is to be tested.

Return Value: This method returns true if this map contains a mapping for the specified key.

Exception: This method throws following exceptions:

NullPointerException: if key is null
ClassCastException: if key is not String
IllegalArgumentException: if key is empty String

Java programs to Illustrate the working of containsKey() method:

Program 1:

// Java program to demonstrate containsKey() method 
  
import javax.script.SimpleBindings; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // create simpleBindings object 
        SimpleBindings bindings = new SimpleBindings(); 
  
        // add some keys with values 
        bindings.put("key1", "value1"); 
        bindings.put("key2", "value2"); 
        bindings.put("key3", "value3"); 
  
        // check key2 is exists in bindings or not 
        boolean isKey2Exist = bindings.containsKey("key2"); 
  
        // print 
        System.out.println("Key2 exits:" + isKey2Exist); 
    } 
} 

Output:

Key2 exits:true

Program 2:

// Java program to demonstrate containsKey() method 
  
import javax.script.SimpleBindings; 
  
public class GFG { 
    public static void main(String[] args) 
    { 
  
        // create simpleBindings object 
        SimpleBindings asiaTeamList 
            = new SimpleBindings(); 
  
        // add team in asiaTeamList 
        asiaTeamList.put("team1", "India"); 
        asiaTeamList.put("team2", "Sri Lanka"); 
        asiaTeamList.put("team3", "Pakistan"); 
        asiaTeamList.put("team4", "Bangladesh"); 
  
        // check England exists in bindings or not 
        boolean isKey2Exist 
            = asiaTeamList.containsKey("England"); 
  
        // print 
        System.out.println("England exits in Asia Team:"
                           + isKey2Exist); 
    } 
} 

Output:

England exits in Asia Team:false

References: https://docs.oracle.com/javase/10/docs/api/javax/script/SimpleBindings.html#containsKey(java.lang.Object)

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