从java中的字符串修剪新行字符

The output of below program:

以下程序的输出：

public class TestClass {

    public static void main(final String[] args){
        String token = "null\n";
        token.trim();
        System.out.println("*");
        System.out.println(token);
        System.out.println("*");
    }
}

is:

是：

*
null

*

However

然而

How to remove newlines from beginning and end of a string (Java)?

如何从字符串的开头和结尾删除换行符（Java）？

says otherwise.

否则说。

What am I missing?

我错过了什么？

2 个解决方案

#1

Since String is immutable

因为String是不可变的

token.trim();

doesn't change the underlying value, it returns a new String without the leading and ending whitespace characters. You need to replace your reference

不更改基础值，它返回一个没有前导和结束空白字符的新String。您需要替换您的参考

token = token.trim();

#2

Strings are immutable. Change

字符串是不可变的。更改

token.trim();

to

至

token = token.trim();