Matcher lookingAt() 方法在 Java 中的示例
java.util.regex.Matcher 类表示执行各种匹配操作的引擎。该类没有构造函数,你可以使用 java.util.regex.Pattern 类的 matches() 方法创建/获取该类的一个对象。
Matcher 类的 lookingAt() 方法从区域开头开始使用模式匹配给定的输入文本。如果匹配,此方法将返回 true,否则返回 false。与 matches() 方法不同,此方法不需要整个区域中的匹配才能返回 true。
示例 1
import java.util.regex.Matcher; import java.util.regex.Pattern; public class Test { public static void main(String[] args) { String regex = "(.*)(\d+)(.*)"; String input = "This is a sample Text, 1234, with numbers in between. " + "\n This is the second line in the text " + "\n This is third line in the text"; //Creating a pattern object Pattern pattern = Pattern.compile(regex); //Creating a Matcher object Matcher matcher = pattern.matcher(input); //checking for the match if(matcher.lookingAt()) { System.out.println("Match found"); } else { System.out.println("Match not found"); } } }
输出
Match found
示例 2
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class LookingAtExample { public static void main(String args[]) { Scanner sc = new Scanner(System.in); System.out.println("Enter String1: "); String input1 = sc.nextLine(); System.out.println("Enter String2: "); String input2 = sc.nextLine(); System.out.println("Enter String3: "); String input3 = sc.nextLine(); String input = input1+"\n"+input2+"\n"+input3; System.out.println(input); //Regular expression to match a word that contain digits String regex = ".*\d+.*"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); //verifying whether match occurred boolean bool = matcher.lookingAt(); if(bool) { System.out.println("Given input contains digit"); } else { System.out.println("Given input does not contain any digit"); } } }
输出
Enter String1: sample text2 Enter String2: data Enter String3: sample sample text2 data sample Given input contains digit
广告