字符类\ p {javaWhitespace} Java中的Java正则表达式。
字符类\p{javaWhitespace}匹配空格。此类与当作为参数传递给isWhitespace()java.lang.Character类的方法时返回true的字符匹配。
例子1
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class RegexExample {
public static void main(String args[]) {
//从用户读取字符串
System.out.println("Enter a string");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
//正则表达式
String regex = "[\\p{javaWhitespace}]";
//Compiling the 正则表达式
Pattern pattern = Pattern.compile(regex);
//检索匹配器对象
Matcher matcher = pattern.matcher(input);
int count = 0;
while(matcher.find()) {
count++;
}
System.out.println("Number of upper case characters: "+count);
}
}输出结果
Enter a string hello welcome to nhooo Number of upper case characters: 3
例子2
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class Example {
public static void main( String args[] ) {
//正则表达式 to match lower case letters
String regex = "^\\p{javaWhitespace}+$";
//获取输入数据
Scanner sc = new Scanner(System.in);
System.out.println("Enter 5 input strings: ");
String input[] = new String[5];
for (int i=0; i<5; i++) {
input[i] = sc.nextLine();
}
//创建一个Pattern对象
Pattern p = Pattern.compile(regex);
System.out.println("Strings with only upper case characters: ");
for(int i=0; i<5;i++) {
//创建一个Matcher对象
Matcher m = p.matcher(input[i]);
if(m.matches()) {
System.out.println(m.group());
}
}
}
}输出结果
Enter 5 input strings: Raju RAMU rahman radha SUnDar* Strings with only upper case characters: RAMU