[해결 방법] error: no suitable method found for ...

👉 기본 환경

- Language: Java

- IDE: Sublime

 

 

⌨️ 코드

import java.util.Arrays;
import java.util.Collections;
 
class Solution {
    public String solution(String s) {
        String answer = "";
        char[] sToCharArr = new char[s.length()];
        for(int i=0; i<s.length(); i++){
            sToCharArr[i] = s.charAt(i);
        }
        Arrays.sort(sToCharArr, Collections.reverseOrder());
        
        StringBuilder sb = new StringBuilder();
        for(int i=s.length()-1; i>-1; i--){
            sb.append(sToCharArr[i]);
        }
        answer = sb.toString();
        return answer;
    }
}
 

 

 

🖨️오류

/Solution.java:11: error: no suitable method found for sort(char[],Comparator<Object>)
        Arrays.sort(sToCharArr, Collections.reverseOrder());
              ^
    method Arrays.<T#1>sort(T#1[],Comparator<? super T#1>) is not applicable
      (inference variable T#1 has incompatible bounds
        equality constraints: char
        lower bounds: Object)
    method Arrays.<T#2>sort(T#2[],int,int,Comparator<? super T#2>) is not applicable
      (cannot infer type-variable(s) T#2
        (actual and formal argument lists differ in length))
  where T#1,T#2 are type-variables:
    T#1 extends Object declared in method <T#1>sort(T#1[],Comparator<? super T#1>)
    T#2 extends Object declared in method <T#2>sort(T#2[],int,int,Comparator<? super T#2>)
 

 

 

📡 원인

기본형 타입에 대한 Comparator가 존재하지 않음

 

 

📰 해결 방법

import java.util.Arrays;
import java.util.Collections;
 
class Solution {
    public String solution(String s) {
        String answer = "";
        String[] sToStringArr = s.split("");
        Arrays.sort(sToStringArr, Collections.reverseOrder());
        
        StringBuilder sb = new StringBuilder();
        for(int i=0; i<sToStringArr.length; i++){
            sb.append(sToStringArr[i]);
        }
        answer = sb.toString();
        return answer;
    }
}
 

객체 타입의 배열 사용

 

 

 

📚 참고 자료

[자바]no suitable method found for sort(int[],(a,b)->Int[...]a, b)) Arrays.sort(numbers, (a, b) -> Integer.compare(a, b