Question

How to loop through a map in Java

Answer 1

import java.util.Map;
 
public class MyClass {
    public static void main(String args[]) {
        Map<Integer, String> map = Map.of(1,"java", 4,"python", 7,"c++", 2,"c");
 
        for (Map.Entry<Integer, String> entry:map.entrySet()) {
            System.out.println("key: " + entry.getKey() + " value: " + entry.getValue());
        }
    }
}
 
 
 
 
/*
run:
 
key: 1 value: java
key: 7 value: c++
key: 4 value: python
key: 2 value: c

*/
 

 

70+ SQL courses for beginners and professionals

Answer 2

import java.util.Map;
 
public class MyClass {
    public static void main(String args[]) {
        Map<Integer, String> map = Map.of(1,"java", 4,"python", 7,"c++", 2,"c");
 
        map.forEach((key, value) -> {
            System.out.format("key: %d, value: %s\n", key, value);
        });
    }
}
 
 
 
 
/*
run:
 
key: 4, value: python
key: 7, value: c++
key: 1, value: java
key: 2, value: c

*/

 

70+ SQL courses for beginners and professionals

Answer 3

import java.util.Map;
import java.util.Iterator;

public class MyClass {
    public static void main(String args[]) {
        Map<Integer, String> map = Map.of(1,"java", 4,"python", 7,"c++", 2,"c");
 
        Iterator it = map.entrySet().iterator();
        while (it.hasNext()) {
            Map.Entry keyalue = (Map.Entry)it.next();
            System.out.println(keyalue.getKey() + " : " + keyalue.getValue());
        }
    }
}
 
 
 
 
/*
run:
 
2 : c
4 : python
7 : c++
1 : java

*/

 

70+ SQL courses for beginners and professionals

Answer 4

import java.util.Map;
import java.util.Iterator;
 
public class MyClass {
    public static void main(String args[]) {
        Map<Integer, String> map = Map.of(1,"java", 4,"python", 7,"c++", 2,"c", 3,"c++");
  
        for (var entry : map.entrySet()) {
            System.out.println(entry.getKey() + " : " + entry.getValue());
        }
    }
}
  
  
  
  
/*
run:
  
7 : c++
4 : python
3 : c++
2 : c
1 : java
 
*/

 

70+ SQL courses for beginners and professionals