StringBuilder的字符操作技巧

使用append()方法来添加字符或字符串到StringBuilder对象中：

StringBuilder sb = new StringBuilder();sb.append("Hello");sb.append(" ");sb.append("World");System.out.println(sb.toString()); // Output: Hello World

使用insert()方法来在指定位置插入字符或字符串到StringBuilder对象中：

StringBuilder sb = new StringBuilder("Hello World");sb.insert(5, ","); // Insert a comma at index 5System.out.println(sb.toString()); // Output: Hello, World

使用delete()方法来删除指定范围内的字符或字符串：

StringBuilder sb = new StringBuilder("Hello, World");sb.delete(5, 7); // Delete characters from index 5 to 7System.out.println(sb.toString()); // Output: Hello World

使用replace()方法来替换指定范围内的字符或字符串：

StringBuilder sb = new StringBuilder("Hello, World");sb.replace(7, 12, "Java"); // Replace characters from index 7 to 12 with "Java"System.out.println(sb.toString()); // Output: Hello, Java

使用reverse()方法来反转StringBuilder对象中的字符序列：

StringBuilder sb = new StringBuilder("Hello");sb.reverse();System.out.println(sb.toString()); // Output: olleH