The Java.util.EnumMap.containsKey(key) method is used to check whether a specified key mentioned in the parameter is present in this map or not.
Syntax:
boolean containsKey(Object key)
Parameter: The method accepts one parameter key which refer to the key to be verified.
Return Value: The method returns true if the key is present in the EnumMap otherwise it returns false.
Below programs illustrate the containsKey() method:
Program 1:
// Java program to demonstrate containsKey() method import java.util.*;
// An enum of gfg visitors is created public enum gfg_visitors {
India,
United_States,
China,
Japan,
Canada
}; class Enum_map {
public static void main(String[] args)
{
EnumMap<gfg_visitors, String> mp = new EnumMap<gfg_visitors, String>(gfg_visitors. class );
// values are associated in mp
mp.put(gfg_visitors.India, "61.4%" );
mp.put(gfg_visitors.United_States, "18.4%" );
mp.put(gfg_visitors.China, "2.5%" );
mp.put(gfg_visitors.Japan, "1.1%" );
mp.put(gfg_visitors.Canada, "1.1%" );
// Check if map contains gfg visitor from United_States
boolean ans = mp.containsKey(gfg_visitors.United_States);
// Prints the result
System.out.println( "gfg_visitors from United States: " + ans);
}
} |
Output:
gfg_visitors from United States: true
Program 2:
// Java program to demonstrate containsKey() method import java.util.*;
// An enum of gfg visitors is created public enum gfg_visitors {
India,
United_States,
China,
Japan,
Canada,
Russia
}; class Enum_map {
public static void main(String[] args)
{
EnumMap<gfg_visitors, String> mp = new EnumMap<gfg_visitors, String>(gfg_visitors. class );
// values are associated in mp
mp.put(gfg_visitors.India, "61.4%" );
mp.put(gfg_visitors.United_States, "18.4%" );
mp.put(gfg_visitors.China, "2.5%" );
mp.put(gfg_visitors.Japan, "1.1%" );
mp.put(gfg_visitors.Canada, "1.1%" );
// check if map contains gfg visitor from Russia
boolean ans = mp.containsKey(gfg_visitors.Russia);
// prints the result
System.out.println( "gfg_visitors from Russia: " + ans);
}
} |
Output:
gfg_visitors from Russia: false