Java foreach이용, collection의 모든object 출력

Java Collection의 모든 object 출력

1. Map

Map<String, String> map = new HashMap<>();
// 1.  
for (String key : map.keySet()) {  
    String value = map.get(key);  
    System.out.println("key : " + key + ", " + "value : " + value);  
}

// 2.  
map.forEach((k, v) -> {  
    System.out.println("key : " + k + ", " + "value : " + v);  
});

2. Set

Set<String> set = new HashSet<>();
// 1. 
for (String str : set) {
    System.out.println("6. " + "set : " + set);
}
// 2.
set.forEach(obj -> {
System.out.println("7. " + "set : " + obj);
});

3. List

List<String> list = new ArrayList<>();  
// 1.  
for (String str: list) {  
    System.out.println("3. " + "list : " + list);  
}  
// 2.  
list.forEach(list -> {  
    System.out.println("5. " + "list : " + list);  
});