String不可变,StringBuffer可变;String操作产生新对象,StringBuffer原地修改;StringBuffer线程安全,String本身不可变故线程安全。 1. **可变性** - **String**:不可变类,任何修改(如拼接、替换)都会生成新对象,原对象不变。 - **StringBuffer**:可变类,修改直接在原对象上进行(如`append()`方法修改内部字符数...
publicclassMain{publicstaticvoidmain(String[] args){/*1*/String string = "a" + "b" + "c";/*2*/StringBuffer stringBuffer =newStringBuffer(); stringBuffer.append("a"); stringBuffer.append("b"); stringBuffer.append("c"); string =stringBuffer.toString(); } } 当时大部分的新手猿友都...
delete(int start,int end)[删除指定区间内的所有字符,包含start,不包含end的区间] StringBuffer sb = new StringBuffer("TestString"); sb.delete(1,4); 删除索引1-3的字符,所以sb的值变为"TString"; c.insert()[在StringBuffer对象中插入内容,形成新的字符串] StringBuffer sb = new StringBuffer(“Tes...
String 不可变，因此是线程安全的StringBuffer与StringBuilderStringBuffer 是线程安全的；StringBuilder 是非线...
Chapter 1 briefly referred to the String type in the context of String[] args . This type showed up in subsequent chapters without a proper discussion. This chapter addresses this oversight by properly introducing you to String . It then introduces String 's companion type: StringBuffer ....
.append(“ and pwd=”) .append(pwd); 这样对象sb的值就是字符串“select * from userInfo where username=test and pwd=123”。 2、deleteCharAt方法 public StringBuffer deleteCharAt(int index) 该方法的作用是删除指定位置的字符,然后将剩余的内容形成新的字符串。例如: ...
上述代码创建了一个String对象str,然后使用StringBuffer的构造函数将其转换为StringBuffer对象stringBuffer。 代码示例 下面是一个简单的示例,展示了如何在Java中使用String和StringBuffer: publicclassStringAndStringBufferDemo{publicstaticvoidmain(String[]args){// 创建一个String对象Stringstr="Hello, World!";// 将...
publicclassDemo02{publicstaticvoidmain(String[] args){StringBuffer sb =newStringBuffer();String user ="yyg";String pwd ="123";//实现SQL语句的拼接 sb.append("select * from userInfo where username=").append(user).append(" and pwd=").append(pwd);System.out.println("sql="+sb.toString()...
StringBuffer作为一个可变字符串类,具有如下特性: ●具有线程安全性:StringBuffer中的公开方法都由synchronized关键字修饰,保证了线程同步; ●带有缓冲区:StringBuffer每次调用toString()方法时,都会直接使用缓存区的toStringCache值来构造一个字符串; ●内容可变性:StringBuffer中带有字符串缓冲区,我们可以通过数组的复制来...
String and StringBuffer HashCode Test Let us do Hash Code testing of String class and String Buffer Class and see what the result is. We have taken objects of both String class and String Buffer Class, than we have appended String value= “Android” to both objects. As shown in the follo...