Regular Expressions 101

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An explanation of your regex will be automatically generated as you type.
Detailed match information will be displayed here automatically.
  • All Tokens
  • Common Tokens
  • General Tokens
  • Anchors
  • Meta Sequences
  • Quantifiers
  • Group Constructs
  • Character Classes
  • Flags/Modifiers
  • Substitution
  • A single character of: a, b or c
    [abc]
  • A character except: a, b or c
    [^abc]
  • A character in the range: a-z
    [a-z]
  • A character not in the range: a-z
    [^a-z]
  • A character in the range: a-z or A-Z
    [a-zA-Z]
  • Any single character
    .
  • Alternate - match either a or b
    a|b
  • Any whitespace character
    \s
  • Any non-whitespace character
    \S
  • Any digit
    \d
  • Any non-digit
    \D
  • Any word character
    \w
  • Any non-word character
    \W
  • Non-capturing group
    (?:...)
  • Capturing group
    (...)
  • Zero or one of a
    a?
  • Zero or more of a
    a*
  • One or more of a
    a+
  • Exactly 3 of a
    a{3}
  • 3 or more of a
    a{3,}
  • Between 3 and 6 of a
    a{3,6}
  • Start of string
    ^
  • End of string
    $
  • A word boundary
    \b
  • Non-word boundary
    \B

Regular Expression

/
/
gm

Test String

Code Generator

Generated Code

import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example { public static void main(String[] args) { final String regex = "(?:^|[^%])(?:%%)*(%(?:\\d+\\$)?(?:\\+)?(?:0|'.)?(?:\\-)?(?:\\d+)?(?:\\.\\d+)?[bcdeEufFgGosxX])"; final String string = "<?php\n" + "$n = 43951789;\n" + "$u = -43951789;\n" + "$c = 65; // ASCII コードの 65 は 'A' です\n\n" + "// %% に注目しましょう。これは、リテラル '%' を文字として出力します\n" + "printf(\"%%b = '%b'\\n\", $n); // 2 進表現\n" + "printf(\"%%c = '%c'\\n\", $c); // ascii 文字を表示します。chr() 関数と同じです\n" + "printf(\"%%d = '%d'\\n\", $n); // 標準の整数表現\n" + "printf(\"%%e = '%e'\\n\", $n); // 科学記法\n" + "printf(\"%%u = '%u'\\n\", $n); // 正の整数の、符号なし整数表現\n" + "printf(\"%%u = '%u'\\n\", $u); // 負の整数の、符号なし整数表現\n" + "printf(\"%%f = '%f'\\n\", $n); // 浮動小数点表現\n" + "printf(\"%%o = '%o'\\n\", $n); // 8 進表現\n" + "printf(\"%%s = '%s'\\n\", $n); // 文字列表現\n" + "printf(\"%%x = '%x'\\n\", $n); // 16 進表現 (小文字)\n" + "printf(\"%%X = '%X'\\n\", $n); // 16 進表現 (大文字)\n\n" + "printf(\"%%+d = '%+d'\\n\", $n); // 正の整数に符号指定子を使用\n" + "printf(\"%%+d = '%+d'\\n\", $u); // 負の整数に符号指定子を使用\n" + "?>\n\n" + "<?php\n" + "$s = 'monkey';\n" + "$t = 'many monkeys';\n\n" + "printf(\"[%s]\\n\", $s); // 標準の文字列出力\n" + "printf(\"[%10s]\\n\", $s); // 空白を使用して右詰め\n" + "printf(\"[%-10s]\\n\", $s); // 空白を使用して左詰め\n" + "printf(\"[%010s]\\n\", $s); // ゼロ埋めは文字列でも可能です\n" + "printf(\"[%'#10s]\\n\", $s); // ゼロの代わりに独自の文字 '#' で埋めます\n" + "printf(\"[%10.10s]\\n\", $t); // 左詰めを行い、10 文字以上は切り捨てます\n" + "?>\n" + "例9 sprintf(): 整数のゼロ埋め\n\n" + "<?php\n" + "$isodate = sprintf(\"%04d-%02d-%02d\", $year, $month, $day);\n" + "?>\n" + "例10 sprintf(): 通貨をフォーマットする例\n\n" + "<?php\n" + "$money1 = 68.75;\n" + "$money2 = 54.35;\n" + "$money = $money1 + $money2;\n" + "// echo $money は \"123.1\" を出力します。\n" + "$formatted = sprintf(\"%01.2f\", $money);\n" + "// echo $formatted は \"123.10\"を出力します\n" + "?>\n" + "例11 sprintf(): 科学記法\n\n" + "<?php\n" + "$number = 362525200;\n\n" + "echo sprintf(\"%.3e\", $number); // 3.625e+8 を出力します\n" + "?>\n\n"; final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE); final Matcher matcher = pattern.matcher(string); while (matcher.find()) { System.out.println("Full match: " + matcher.group(0)); for (int i = 1; i <= matcher.groupCount(); i++) { System.out.println("Group " + i + ": " + matcher.group(i)); } } } }

Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Java, please visit: https://docs.oracle.com/javase/7/docs/api/java/util/regex/Pattern.html