Java 基础之StringBuilder类

常用方法：

public class Main {

    public static void main(String[] args) {
        StringBuilder builder=new StringBuilder();
        
        //所有修改都针对自身，并没有一个新的builder返回
        //字符串连接
        builder.append("Hello");
        builder.append(" World");
        System.out.println(builder.toString());

        //定位字符串
        System.out.println(builder.indexOf("W"));

        //字符串替换
        builder.replace(1,4,"ooo");
        System.out.println(builder.toString());

        //字符串插入
        builder.insert(1,"ello");
        System.out.println(builder.toString());

        //字符串删除
        builder.delete(4,8);
        System.out.println(builder.toString());

        //定位
        System.out.println(builder.lastIndexOf("o"));


        //长度
        System.out.println(builder.length());

        //字符串反转
        builder.reverse();
        System.out.println(builder.toString());

    }
}

运行结果：