Java 使用一个简单的扫描仪，读取一个带空格的字符串，为什么 .trim() 方法不起作用？
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Using a simple scanner, reading a string with spaces, how come .trim() method isn't working?
提问by WM.
import java.util.Scanner;
import java.lang.String;
public class Test
{
public static void main(String[] args)
{
char[] sArray;
Scanner scan = new Scanner(System.in);
System.out.print("Enter a Palindrome : ");
String s = scan.nextLine();
s = s.trim();
sArray = new char[s.length()];
for(int i = 0; i < s.length(); i++)
{
sArray[i] = s.charAt(i);
System.out.println(sArray[i]);
}
}
}
采纳答案by jjnguy
Trim doesn't work how you expect it to. trim()only removes whitespace from the ends of the string.
Trim 不能像您期望的那样工作。 trim()只从字符串的末尾删除空格。
的文档trim()：
Returns a copy of the string, with leadingand trailingwhitespace omitted.
返回字符串的副本，省略前导和尾随空格。
To remove all whitespace try the following instead of calling trim():
要删除所有空格，请尝试以下操作而不是调用trim()：
s = s.replaceAll("\s+", "");
This uses a very simple regular expression to remove all whitespace anywhere in the string.
这使用一个非常简单的正则表达式来删除字符串中任何位置的所有空格。
回答by SLaks
The trimfunction removes leading and trailingspaces, not all spaces.
该trim函数删除前导和尾随空格，而不是所有空格。
If you want to remove all spaces, you can call s = s.replaceAll(" ", "").
如果要删除所有空格，可以调用s = s.replaceAll(" ", "").
回答by Ted Betz
great answer jjnguy and slals
很好的答案 jjnguy 和 slals
I now use
我现在用
myinput = myEditTextbox.getText().toString;
myinput = myinput.replaceAll("\S+", "");
to clean out all spaces accidentally left in an edittext box by the user. It also directed me to learn about regular expressions that I didn't know about. Thanks
清除用户意外留在编辑文本框中的所有空间。它还指导我学习我不知道的正则表达式。谢谢
