Question

How to update value of HashMap using key in Java

Answer 1

import java.util.HashMap;

public class MyClass {
    public static void main(String args[]) {
        HashMap<String, String> hm = new HashMap<>();
 
        hm.put("Java", "ABC");
        hm.put("C++", "AAB");
        hm.put("Python", "ACB");
        hm.put("C", "AAA");
        hm.put("PHP", "ACD");
 
        String value = hm.get("Python");

        value = "BBB";

        hm.put("Python", value);
        
        System.out.println(hm);
    }
}
  
  
  
  
/*
run:
    
{Java=ABC, C++=AAB, C=AAA, PHP=ACD, Python=BBB}
  
*/

 

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Answer 2

import java.util.HashMap;

public class MyClass {
    public static void main(String args[]) {
        HashMap<String, Integer> hm = new HashMap<>();
 
        hm.put("Java", 1);
        hm.put("C++", 2);
        hm.put("Python", 3);
        hm.put("C", 4);
        hm.put("PHP", 5);
 
        String key = "Python";
        
        hm.put(key, hm.get(key) + 10); 

        
        System.out.println(hm);
    }
}
  
  
  
  
/*
run:
    
{Java=1, C++=2, C=4, PHP=5, Python=13}
  
*/

 

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