输入不会 trim

Question

这是全新的，但我不确定我做错了什么，因为输出不会 trim。

package cs520.hw3.part1;

import javax.swing.JOptionPane;

public class StringTest {

    public static void main(String[] args) {

        String input = JOptionPane.showInputDialog("Enter data using the format Name, Age, City");
        //String delimiter = ",";
        //String[] tokens = input.split(delimiter);
        System.out.println(input.trim());
    }
}

Answer 1

trim() 方法 returns 删除前导和尾随白色 space 的字符串副本，或者相同的字符串，如果它没有前导或尾随白色 space.

示例：

import java.io.*;
public class Test {

   public static void main(String args[]) {
      String Str = new String("   Some string with whitespace in front and after it.   ");

      System.out.print("Return Value :" );
      System.out.println(Str.trim() );
   }
}

输出：

Return Value :Some string with whitespace in front and after it.

Answer 2

删除前导和尾随空格（使用 trim() 和替换 String 中的 all 空格（使用 replaceAll(" ", ""))

示例输出

' Andrew,      52,  Sydney         '
'Andrew,      52,  Sydney'
'Andrew,52,Sydney'

原始字符串
trim()
replaceAll(" ", "")

代码

import javax.swing.*;

public class TrimSpace {
    
    TrimSpace() {
        String s = JOptionPane.showInputDialog(null, 
                "Name, Age, City", 
                "Person Details", 
                JOptionPane.QUESTION_MESSAGE);
        // show the raw string entered by user
        System.out.println(String.format("'%1s'", s));
        // remove leading & trailing space from string
        System.out.println(String.format("'%1s'", s.trim()));
        // remove all spaces from string
        System.out.println(String.format("'%1s'", s.replaceAll(" ", "")));
    }
    
    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                new TrimSpace();
            }
        };
        SwingUtilities.invokeLater(r);
    }
}

输入不会 trim

Input won't trim

java

swing

input

joptionpane

示例输出

代码