如何使用Java正则表达式(RegEx)删除空格
正则表达式“\\s”与字符串中的空格匹配。该replaceAll()方法接受字符串，并且正则表达式用给定的字符串替换匹配的字符。要从输入字符串中删除所有空白，请绕过上面提到的正则表达式和一个空字符串作为输入，在其上调用replaceAll()方法。
例子1
public class RemovingWhiteSpaces {
public static void main( String args[] ) {
String input = "Hi welcome to nhooo";
String regex = "\\s";
String result = input.replaceAll(regex, "");
System.out.println("Result: "+result);
}
}输出结果
Result: Hiwelcometonhooo
例子2
类似地，appendReplacement()方法接受一个字符串缓冲区和一个替换字符串，并使用给定的替换字符串附加匹配的字符，并将其附加到字符串缓冲区。
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RemovingWhiteSpaces {
public static void main( String args[] ) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter input string: ");
String input = sc.nextLine();
String regex = "\\s";
String constants = "";
System.out.println("Input string: \n"+input);
//创建一个模式对象
Pattern pattern = Pattern.compile(regex);
//匹配字符串中的已编译模式
Matcher matcher = pattern.matcher(input);
//创建一个空的字符串缓冲区
StringBuffer sb = new StringBuffer();
while (matcher.find()) {
constants = constants+matcher.group();
matcher.appendReplacement(sb, "");
}
matcher.appendTail(sb);
System.out.println("Result: \n"+ sb.toString()+constants );
}
}输出结果
Enter input string: this is a sample text with white spaces Input string: this is a sample text with white spaces Result: thisisasampletextwithwhitespaces
例子3
public class Just {
public static void main(String args[]) {
String input = "This is a sample text with spaces";
String str[] = input.split(" ");
String result = "";
for(int i=0; i<str.length; i++) {
result = result+str[i];
}
System.out.println("Result: "+result);
}
}输出结果
Result: Thisisasampletextwithspaces