I can print the value using key, but I can't able to print the key using its value.
Source code
public class test {
public static void main(String[] args) {
Map<Integer, String> hashMap = new HashMap<>();
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number of element to insert in map:");
int num = sc.nextInt();
sc.nextLine();
for (int i = 0; i < num; i ) {
System.out.print("Enter a Key:");
int num1 = sc.nextInt();
sc.nextLine();
System.out.print("Enter a value:");
String str1 = sc.nextLine();
hashMap.put(num1, str1);
}
System.out.println(hashMap);
System.out.println(hashMap.get(1));
sc.close();
}
}
Program Output
Enter a number of element to insert in map:2
Enter a Key:1
Enter a value:a
Enter a Key:2
Enter a value:b
{1=a, 2=b}
a
CodePudding user response:
For example, you want to find key using value abc:
String res;
HashMap<String, String> hashMap = new HashMap<>();
Set<Map.Entry<String, String>> entrySet = hashMap.entrySet();
for (Map.Entry<String, String> entry : entrySet) {
if (entry.getValue().equals("abc")) {
res = entry.getKey();
break;
}
}
System.out.println(res);