正则表达式Regex

//简单认识正则表达式
p("abc".matches("..."));
p("a1234a".replaceAll("\d","^"));
Pattern p = Pattern.compile("[a-z]{3}");
Matcher m = p.matcher("hll");
p(m.matches());

p("a".matches("."));
p("aa".matches("a*"));
p("aa".matches("aa"));
p("aaaa".matches("a*"));
p("aaaa".matches("a+"));
p("".matches("a?"));
p("".matches("a*"));

//大于12
p("1242343242342".matches("\d{3,12}"));
p("1242343242342".matches("\d{3,22}"));
p("192.168.255.2".matches("\d{1,3}\.\d{1,3}\.\d{1,3}\.\{0,3}"));
p("192".matches("[0-2][0-9][0-9]"));

//认识s w d
p(" ".matches("\s(4)"));
p(" ".matches("\S"));
p("a_8".matches("\w(8)"));
p("ac4433221&*".matches("[a-z]{1,3}\d+[&*^]+"));

//boundary
p("hello sir".matches("^h.*"));
p("hello sir".matches(".*ir$"));
p("hello sir".matches("^h[a-z]{1,3}o\b.*"));
p("hellosir".matches("^h[a-z]{1,3}o\b.*"));
p(" ".matches("^[\s&&[^\n]]*\n$"));//white lines