[JAVA] List에 Stream으로 값 넣기

String to list(String)

        String[] str = {"apple", "banana", "cherry", "date", "elderberry", "fig"};

        List<String> list = Arrays.stream(str).collect(Collectors.toList());
        
        // Java 16 버전부터 가능
        List<String> list = Arrays.stream(str).toList();

 

 

Int to list(Integer)

        int[] arr = {1,2,3,4,5,6};
        List<Integer> list = Arrays.stream(arr).boxed().toList();

 

 

 

Char to list(char)

        char[] charArr = {'a', 'b', 'c', 'd', 'e'};

        List<Character> charList = new String(charArr).chars()
                .mapToObj(c -> (char) c)
                .collect(Collectors.toList());
        
        // Java 16 버전부터 가능
        List<Character> charList = new String(charArr).chars()
                .mapToObj(c -> (char) c)
                .toList();

 

 

 

String to list(char)

        String chars = "HelloWorld";

        List<Character> listChar = chars.chars().mapToObj(c -> (char) c).collect(Collectors.toList());

        // Java 16 버전부터 가능
        List<Character> listChar = chars.chars().mapToObj(c -> (char) c).toList();

 

 

 

String to list(Integer)

        String strInt = "1234567";

        List<Integer> listStringToInteger = strInt.chars()
                .mapToObj(c -> Character.getNumericValue((char) c))
                .collect(Collectors.toList());

        // Java 16 버전부터 가능
        List<Integer> listStringToInteger = strInt.chars()
                .mapToObj(c -> Character.getNumericValue((char) c))
                .toList();

 

 

Int to list(String)

       int[] intArr = {1, 2, 3, 4, 5};

        List<String> listIntToString = Arrays.stream(intArr)
                .mapToObj(String::valueOf)
                .collect(Collectors.toList());

        // Java 16 버전부터 가능
        List<String> listIntToString = Arrays.stream(intArr)
                .mapToObj(String::valueOf)
                .toList();