Java String charAt() 方法

import java.lang.*;

public class StringDemo {

   public static void main(String[] args) {

      String str = "This is codingdict";

      // prints character at 1st location

      System.out.println(str.charAt(0));



      // prints character at 5th location i.e white-space character

      System.out.println(str.charAt(4));



      // prints character at 18th location

      System.out.println(str.charAt(17));

   }

}