在 Java 中解释正则表达式“s”元字符
子表达式/元字符“\s”匹配空等效项。
示例 1
import java.util.regex.Matcher; import java.util.regex.Pattern; public class RegexExample { public static void main( String args[] ) { String regex = "\s"; String input = "Hello how are you welcome to Tutorialspoint !"; Pattern p = Pattern.compile(regex); Matcher m = p.matcher(input); int count = 0; while(m.find()) { count++; } System.out.println("Number of matches: "+count); } }
输出
Number of matches: 7
示例 2
以下示例读取一个字符串,并移除其中的所有多余空格。
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String args[]) { //Reading String from user System.out.println("Enter a String"); Scanner sc = new Scanner(System.in); String input = sc.nextLine(); //Regular expression to match spaces (one or more) String regex = "\s+"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); //Replacing all space characters with single space String result = matcher.replaceAll(" "); System.out.print("Text after removing unwanted spaces: \n"+result); } }
输出
Enter a String hello this is a sample text with irregular spaces Text after removing unwanted spaces: hello this is a sample text with irregular spaces
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