# Java – How to find Maximum and Minimum Key/Value in a Map ?

In this article, we will discuss how to find maximum & minimum Map Key & Value

# 1. Maximum & Minimum Map Key :

• Map.keySet() provides set of keys from a Map or HashMap
• To find maximum & minimum Map Key, use Collections.max() and Collections.min() methods passing set of keys as argument

### FindMaximumMinimumMapKey.java

```package in.bench.resources.find.entry.map;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class FindMaximumMinimumMapKey {

public static void main(String[] args) {

// 1. creating HashMap object of type <Integer, String>
Map<Integer, String> populationCountry = new HashMap<>();

// 1.1 adding key-value pairs to HashMap object
populationCountry.put(220892331, "Pakistan");
populationCountry.put(146748590, "Russia");
populationCountry.put(213728559, "Brazil");
populationCountry.put(382357386, "Indian");
populationCountry.put(332429717, "America");

// 1.2 print original Map entries
System.out.println("1. Original Map Entries :- \n");

// 1.3 print Map entries to console
populationCountry.forEach((key, value) -> System.out.println(
"Key : " + key  + "\t\t"  + "Value : "  + value
));

// 2. maximum Key in a Map
int max = Collections.max(populationCountry.keySet());

// 2.1 print to console
System.out.println("\n\n2. Maximum Map Key is = " + max);

// 3. maximum Key in a Map
int min = Collections.min(populationCountry.keySet());

// 3.1 print to console
System.out.print("\n3. Minimum Map Key is = " + min);
}
}
```

### Output :

```1. Original Map Entries :-

Key : 382357386		Value : Indian
Key : 220892331		Value : Pakistan
Key : 146748590		Value : Russia
Key : 213728559		Value : Brazil
Key : 332429717		Value : America

2. Maximum Map Key is = 382357386

3. Minimum Map Key is = 146748590
```

# 2. Maximum & Minimum Map Value :

• Map.values() provides list of values from a Map or HashMap
• To find maximum & minimum Map Value, use Collections.max() and Collections.min() methods passing list of values as argument

### FindMaximumMinimumMapValue.java

```package in.bench.resources.find.entry.map;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

public class FindMaximumMinimumMapValue {

public static void main(String[] args) {

// 1. creating HashMap object of type <Integer, String>
Map<String, Integer> countryPopulation = new HashMap<>();

// 1.1 adding key-value pairs to HashMap object
countryPopulation.put("Pakistan", 220892331);
countryPopulation.put("Russia", 146748590);
countryPopulation.put("Brazil", 213728559);
countryPopulation.put("Indian", 382357386);
countryPopulation.put("America", 332429717);

// 1.2 print original Map entries
System.out.println("1. Original Map Entries :- \n");

// 1.3 print Map entries to console
countryPopulation.forEach((key, value) -> System.out.println(
"Key : " + key  + "\t\t"  + "Value : "  + value
));

// 2. Maximum Value in a Map
int max = Collections.max(countryPopulation.values());

// 2.1 print to console
System.out.println("\n\n2. Maximum Map Value is = " + max);

// 3. Maximum Value in a Map
int min = Collections.min(countryPopulation.values());

// 3.1 print to console
System.out.print("\n3. Minimum Map Value is = " + min);
}
}
```

### Output :

```1. Original Map Entries :-

Key : Pakistan		Value : 220892331
Key : America		Value : 332429717
Key : Brazil		Value : 213728559
Key : Indian		Value : 382357386
Key : Russia		Value : 146748590

2. Maximum Map Value is = 382357386

3. Minimum Map Value is = 146748590
```

## References :

Happy Coding !!
Happy Learning !!