String change = "";
for (int i = 0; i < chr.length; i++) {
change += Character.toString(chr[i]);
}
String str = "hi, everyone";
//string → char[]
char[] chr = str.toCharArray();
//char[] → string
String newstr = new String(chr, 0, chr.length);
System.out.println(newstr);
String str = "";
char ch = 'A';
str = String.valueOf(ch);
str = Character.toString(ch);
str = new Character(ch).toString();