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
Processing...

Test String

Code Generator

Language

Generated Code

using System; using System.Text.RegularExpressions; public class Example { public static void Main() { string pattern = @"<{if \$data\.nowPage>1}>.*?</div>\R*<{/if}>"; string input = @" I'm looking for a regular expression to delete htmlA. The border start from <{if $data.nowPage>1}> to /div> 1 breakLine <{/if}> htmlA <{if $data.nowPage>1}> <div class=""pageArrow pageFirst""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=1""><span class=""icon arrow-first""></span></a></div> <div class=""pageArrow pagePrev""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=<{$data.nowPage-1}>""><span class=""icon arrow-left""></span></a></div> <{/if}> I have tried $fullHtml = readFileData($file); preg_match(""/(<{if \\\$data\.nowPage>1}>(.*?)<\/div>)(\s)(.+?)<{\/if}>/si"",$fullHtml,$htmlA); //$fullHtml = preg_replace(...,'',$fullHtml); but it stopped too early and why print_r($htmlA) shows 5 keys? Array ( [0] => <{if $data.nowPage>1}> <div class=""pageArrow pageFirst""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=1""><span class=""icon arrow-first""></span></a></div> <div class=""pageArrow pagePrev""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}> [1] => <{if $data.nowPage>1}> <div class=""pageArrow pageFirst""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=1""><span class=""icon arrow-first""></span></a></div> [2] => <div class=""pageArrow pageFirst""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=1""><span class=""icon arrow-first""></span></a> [3] => [4] => <div class=""pageArrow pagePrev""><a href=""?<{if !empty($data.years)}>y=<{$data.years}> ) fullHtml. line3 to line6. <div class=""pageContainer""> <div class=""pageBox""> <{if $data.nowPage>1}> <div class=""pageArrow pageFirst""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=1""><span class=""icon arrow-first""></span></a></div> <div class=""pageArrow pagePrev""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=<{$data.nowPage-1}>""><span class=""icon arrow-left""></span></a></div> <{/if}> <{for $i=$data.nowPage-$data.pageFit to $data.totalPage}> <{if $data.nowPage == ($i)}> <div class=""pageBtn active""><a href=""javascript:void(0);""><{$i}></a></div> <{else if $i>($data.nowPage+$data.pageFit)}> <div class=""pageMore""><span class=""icon moreIcon""></span></div> <{break}> <{else if $i>0}> <{if $i==$data.nowPage-$data.pageFit && $i>1}> <div class=""pageMore""><span class=""icon moreIcon""></span></div> <{/if}> <div class=""pageBtn""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=<{$i}>""><{$i}></a></div> <{else}> <{/if}> <{/for}> <{if $data.nowPage<$data.totalPage}> <div class=""pageArrow pageNext""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=<{$data.nowPage+1}>""><span class=""icon arrow-right""></span></a></div> <div class=""pageArrow pageLast""><a href=""?<{if !empty($data.years)}>y=<{$data.years}><{/if}><{if !empty($data.month)}>&m=<{$data.month}><{/if}>&p=<{$data.totalPage}>""><span class=""icon arrow-last""></span></a></div> <{/if}> </div> </div>"; RegexOptions options = RegexOptions.IgnoreCase | RegexOptions.Singleline; foreach (Match m in Regex.Matches(input, pattern, options)) { Console.WriteLine("'{0}' found at index {1}.", m.Value, m.Index); } } }

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 C#, please visit: https://msdn.microsoft.com/en-us/library/system.text.regularexpressions.regex(v=vs.110).aspx