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Java - iterate over values in HashMap
1
points
Short solution - using forEach() from Java 8:
Map<String, Integer> map = new HashMap<>();
map.values().forEach(value -> {
// use value variable
System.out.println("Value: " + value);
});
Short solution - using for loop and Map values():
Map<String, Integer> map = new HashMap<>();
for (Integer value : map.values()) {
System.out.println("Value: " + value);
}
Short solution - iterate over entire map and use only values with forEach() from Java 8:
Map<String, Integer> map = new HashMap<>();
map.forEach((key, value) -> {
// we use only value variable
System.out.println("Value : " + value);
});
Short solution - iterate over entire map with entrySet() and use only values:
Map<String, Integer> map = new HashMap<>();
for (Map.Entry<String, Integer> entry : map.entrySet()) {
// String key = entry.getKey();
Integer value = entry.getValue();
System.out.println("Value : " + value);
}
1. Using forEach() from Java 8
import java.util.HashMap;
import java.util.Map;
public class Example1 {
public static void main(String[] args) {
Map<String, Integer> map = new HashMap<>();
map.put("A", 10);
map.put("B", 20);
map.put("C", 30);
map.values().forEach(value -> {
// use value variable
System.out.println("Value: " + value);
});
}
}
Output:
Value: 10
Value: 20
Value: 30
2. Using for loop and Map values()
import java.util.HashMap;
import java.util.Map;
public class Example2 {
public static void main(String[] args) {
Map<String, Integer> map = new HashMap<>();
map.put("A", 10);
map.put("B", 20);
map.put("C", 30);
for (Integer value : map.values()) {
System.out.println("Value: " + value);
}
}
}
Output:
Value: 10
Value: 20
Value: 30
3. Using forEach() from Java 8 on entire map
We can also iterate over entire map and use only values with forEach() from Java 8.
import java.util.HashMap;
import java.util.Map;
public class Example3 {
public static void main(String[] args) {
Map<String, Integer> map = new HashMap<>();
map.put("A", 10);
map.put("B", 20);
map.put("C", 30);
map.forEach((key, value) -> {
// we use only value variable
System.out.println("Value : " + value);
});
}
}
Output:
Value : 10
Value : 20
Value : 30
4. Using entrySet()
We can also iterate over entire map with entrySet() and use only values.
import java.util.HashMap;
import java.util.Map;
public class Example4 {
public static void main(String[] args) {
Map<String, Integer> map = new HashMap<>();
map.put("A", 10);
map.put("B", 20);
map.put("C", 30);
for (Map.Entry<String, Integer> entry : map.entrySet()) {
//String key = entry.getKey();
Integer value = entry.getValue();
System.out.println("Value : " + value);
}
}
}
Output:
Value : 10
Value : 20
Value : 30