1234567891011121314151617Regex regex = new Regex(@"[/u00FF-/uFFFF]+"); // The characters, whoes value are smaller than 0xff, are not expected to be matched. for (int i = 0; i < 0xff; i++) { string s = new string(new char[] { (char)i }); Debug.Assert( !regex.IsMatch(s), string.Format("The character was not expected to be matched: 0x{0:X}!", i)); } // However, the characters whoes value are greater than 0xfe are expected to be matched. for (int i = 0xff; i <= 0xffff; i++) { string s = new string(new char[] { (char)i }); Debug.Assert( regex.IsMatch(s), string.Format("The character was expected to be matched: 0x{0:X}!", i)); }
这时的运行结果是正常的，没有任何的断言错误出现。
然而当使用忽略大小写的匹配模式时，结果就不一样了。将上面代码中的第一行改成：
1Regex regex = new Regex(@"[/u00FF-/uFFFF]+", RegexOptions.IgnoreCase);
1234567891011121314151617var re = /[/u00FF-/uFFFF]+/; // var re = /[/u00FF-/uFFFF]+/i; for(var i=0; i<0xff; i++) { var s = String.fromCharCode( i ); if ( re.test(s) ){ alert( 'Should not be matched: ' + i + '!' ); } } for(var i=0xff; i<=0xffff; i++) { var s = String.fromCharCode( i ); if ( !re.test(s) ){ alert( 'Should be matched: ' + i + '!' ); } }
