형 변환 int -> String (int to String)/ String -> int (String to int)

int -> String (int to String)

1.
Integer.valueOf(String);

2.
Integer.parseInt(String);

String -> int (String to int)

1.
String.valueOf(int);

2. 
Integer.toString(int);

3.
"" + int

적용 예제

package programmersCodingTest.codingTest.level0;

public class 더_크게_합치기 {

    public static int solution(int a, int b) {
        //String temp1 = "" + a + b;
        String temp1 = String.valueOf(a) +  Integer.toString(b);
        String temp2 = "" + b + a;

        //int ab = Integer.parseInt(temp1);
        int ab = Integer.valueOf(temp1);
        int ba = Integer.parseInt(temp2);

        int answer = (ab > ba) ? ab : ba ;
        return answer;
    }

    public static void main(String[] args) {

        System.out.println(solution(9, 91));

    }
}