如何使用 Java 正则表达式在不区分大小写的情况下匹配字符串。
patter 类的编译方法接受两个参数 −
- 表示正则表达式的字符串值。
- Pattern 类的一个域字段的整数值。
Pattern 类的 CASE_INSENSITIVE 域字段匹配不区分大小写的字符。因此,如果你与你的正则表达式一起将一个标志值传递给 compile() 方法,大小写字符都将被匹配。
示例 1
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main( String args[] ) { Scanner sc = new Scanner(System.in); System.out.println("Enter input data: "); String input = sc.nextLine(); //Regular expression to find the required character String regex = "test"; //Compiling the regular expression Pattern pattern = Pattern.compile(regex);//, Pattern.CASE_INSENSITIVE); //Retrieving the matcher object Matcher matcher = pattern.matcher(input); int count =0; while (matcher.find()) { count++; } System.out.println("Number of occurrences: "+count); } }
输出
Enter input data: test TEST Test sample data Number of occurrences: 3
示例 2
import java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class VerifyBoolean { public static void main(String args[]) { Scanner sc = new Scanner(System.in); System.out.println("Enter a string value: "); String str = sc.next(); Pattern pattern = Pattern.compile("true|false", Pattern.CASE_INSENSITIVE); Matcher matcher = pattern.matcher(str); if(matcher.matches()){ System.out.println("Given string is a boolean type"); } else { System.out.println("Given string is not a boolean type"); } } }
输出
Enter a string value: TRUE Given string is a boolean type
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