预定义字符类演示

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预定义字符类演示

. 任何字符
\d 数字：[0-9]
\D 非数字： [^0-9]
\s 空白字符：[ \t\n\x0B\f\r]
\t 水平制表符 \n换行 \x0B垂直制表符 \f翻页 \r回车
\S 非空白字符：[^\s]
\w 单词字符：[a-zA-Z_0-9]
\W 非单词字符：[^\w]

package com.heima.regex;
public class Demo03_Regex {
	public static void main(String[] args) {
		//demo1();
		//demo2();
		//demo3();
		//demo4();
		//demo5();
		//demo6();
		String regex = "\\W";
		System.out.println("a".matches(regex));
		System.out.println("z".matches(regex));
		System.out.println("_".matches(regex));
		System.out.println("%".matches(regex));
	}

	private static void demo6() {
		String regex = "\\w";
		System.out.println("a".matches(regex));
		System.out.println("z".matches(regex));
		System.out.println("_".matches(regex));
		System.out.println("%".matches(regex));
	}

	private static void demo5() {
		String regex = "\\S";
		System.out.println(" ".matches(regex));
		System.out.println("	".matches(regex));
		System.out.println("a".matches(regex));
	}

	private static void demo4() {
		String regex = "\\s";
		System.out.println(" ".matches(regex));
		System.out.println("	".matches(regex)); 				//一个tab键
		System.out.println("    ".matches(regex)); 				//四个空格
	}

	private static void demo3() {
		String regex = "\\D";
		System.out.println("0".matches(regex));
		System.out.println("9".matches(regex));
		System.out.println("a".matches(regex));
	}

	private static void demo2() {
		String regex = "\\d";					//\代表转义字符,如果想表示\d的话,需要\\d
		System.out.println("0".matches(regex));
		System.out.println("a".matches(regex));
		System.out.println("9".matches(regex));
	}

	private static void demo1() {
		String regex = "..";
		System.out.println("a".matches(regex));
		System.out.println("ab".matches(regex));
	}
}