java中StringBuffer的用法
2.StringBuffer
StringBuffer:String类同等的类,它允许字符串改变(原因见上一段所说)。Overall, this avoids creating many temporary (临时)strings, in other words, without StringBuffer, you must create many temporary strings. StringBuffer的内部实现原理:马克-to-win,Every string buffer(缓存) has a capacity(容量). As long as the length of the character sequence contained in the string buffer does not exceed(超过) the capacity, it is not necessary to allocate(分配) a new internal buffer array. If the internal buffer overflows(满后溢出), it is automatically made larger.附带一句:从JDK5开始引入StringBuilder类,它是简易的StringBuffer,速度更快,但线程不安全
public class Test {
public static void main(String[] args) {
StringBuffer buffer;
buffer = new StringBuffer();
buffer.append("1");
System.out.println(buffer);
buffer.append("2");
System.out.println(buffer);
}
}
3.Arrays:
Arrays defined in java.util package
It gives a lots of static methods to manipulate(操纵) array.
int[] result = new int[k];
Arrays.sort(result);
import java.util.Arrays;
public class Test {
public static void main(String[] args) {
int[] result = { 4, 5, 2, 7, 8 };
Arrays.sort(result);//当我们用到jdk自带的sort方法时,一下就排好序了,记得第一章,我们自己排序时,有多麻烦吗?
for (int i = 0; i < result.length; i++) {
System.out.println("" + result[i]);
}
}
}
更多内容请见原文,原文转载自:https://blog.csdn.net/qq_44639795/article/details/101552193
最新文章
- [codevs 2800]送外卖
- VIM 常用快捷键
- JAVA 多线程随笔 (一) 可见性和volatile关键字
- [Angularjs]表单验证
- Delphi面向对象的方法
- AOP这些应用场景(交叉业务)
- 图示-Centos7完整安装
- DATASNAP为支持FIREDAC而增加的远程方法的数据类型TFDJSONDataSets
- svn项目导入
- Linux中tshark(wireshark)抓包工具使用方法详解
- 设计模式总结(Java)—— 适配器模式
- phpstudy APACHE支持.htaccess以及 No input file specified解决方案
- 【BZOJ3140】消毒(二分图匹配)
- 【记录】IntelliJ IDEA—IDEA2018-2019激活
- theano安装问题
- Git综合使用命令行和gui工具小结
- SpringBoot之加载自定义配置文件
- ISAPI多进程设置
- Git之右键没有Git Bash Here的解决办法
- ng-model绑定的是ng-option中的什么?