输出我有一个问题,请参见下面的代码:替换字符串和Java中
public void readFile(String path,String pathName,int num){
try{
PrintWriter out2=new PrintWriter(new PrintWriter(path));
File a=new File(pathName);
Scanner b=new Scanner(a);
while(b.hasNextLine()){
String message=b.nextLine();
Scanner h=new Scanner(message);
while(h.hasNext()){
String f=h.next();
if (f.equals("are")){
f.replace("are","ARE");
}
}
out2.printf("%s",message);
out2.println();
.......
的扫描器读取的文件内容是
who are you?
how are you?
what is up!
然而,当我运行上面的代码和输出到新文件与输入文件相同,这意味着“是”不会被“ARE”取代,我不知道哪个部分是错误的,请告知,谢谢你们!
你在调用'String.replace'并忽略输出。字符串在Java中是不可变的。 –
@JonSkeet是对的。你应该看看文档:) –