Java中字符数组和字符串与StringBuilder和字符串转换的讲解

String str = “abc”；char[] a = str.toCharArray();

char b = str.charAt(1);str.length();a.length;

String str = String.valueOf(a)；

Character c = Character.valueOf(a[1]);

StringBuilder sb = new StringBuilder();for(int i = 0; i < a.length; i++)sb.append(a[i]);

StringBuilder sb = new StringBuilder(str)

String str = sb.toString();

sb.delete(0,n)