Java中具有示例的Matching lookingAt()方法
java.util.regex.Matcher类表示执行各种匹配操作的引擎。此类没有构造函数,可以使用类java.util.regex.Pattern的matchs()方法创建/获取此类的对象。
Matcher类的lookingAt()方法从区域的开头开始将给定的输入文本与模式匹配。如果匹配,则此方法返回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都可以返回true。
例子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"); } } }
输出结果
Match found
例子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"); } } }
输出结果
Enter String1: sample text2 Enter String2: data Enter String3: sample sample text2 data sample Given input contains digit