Java Data Type - 如何替换字符串中的字母

The replace() method takes an old character and a new character as arguments. 



It returns a new String object by replacing all occurrences of the old character 
by the new character. For example,



public class Main {
  public static void main(String[] args) {
    String oldStr = new String("tooth");
    String newStr  = oldStr.replace('o', 'e');
    System.out.println(newStr);
  }
}