char[],char, int, string 간 변환 in java

String -> int 

String str= "42";
int num = Integer.parseInt(str);

String(16진수) -> int 

String hex="1B3";
int num =Integer.parseInt(hex,16);

int  -> String 

String str= Integer.parseString(num);
String str = String.valueOf(num);

int-> Char

int num;
char c= (char)(num+'0');

 

Char -> int 

char ch= '2';
int num = Character.getNumericValue(ch);
int num = (int)ch;

 

 

Char -> String 

char ch='t'
String str = String.valueOf(ch); // most efficient
String str = Character.toString(ch); 
String str = ch + ""; //concatenation 때문에 덜 효율적이다.

 

Char[] -> String 

char [] arr ={'1','2','3'};
String s = new String(arr);
System.out.println(s);

출처:

( int-> char) :

https://www.it-swarm.dev/ko/java/%EC%9E%90%EB%B0%94%EC%97%90%EC%84%9C-int%EB%A5%BC-char%EB%A1%9C-%EB%B3%80%ED%99%98%ED%95%98%EC%8B%AD%EC%8B%9C%EC%98%A4/1040653535/

(Char[] -> String):

https://www.geeksforgeeks.org/convert-character-array-to-string-in-java/