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
  • Match everything enclosed
    (?:...)
  • Capture everything enclosed
    (...)
  • 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
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

const regex = /EGA\d{11}/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('EGA\\d{11}', 'gm') const str = `Skip to main content Skip to local navigation Skip to EBI global navigation menu Skip to expanded EBI global navigation menu (includes all sub-sections) EMBL European Bioinformatics Institute Services Research Training About us European Nucleotide Archive Examples: BN000065, histoneSearchAdvanced Sequence Home Search & Browse Submit & Update Software About ENA Support ENA > Submit & Update > Data formats > Read domain formats Read domain formats This page provides information on the read domain formats in ENA. If you are planning to submit read data into ENA, please refer first to Submitting read data. Data format Metadata format Accession number format Archive generated fastq file format Data format Read data including bases, base qualities and alignments can be submitted in several different formats ... more information. Metadata format The metadata model consists of several objects each represented using XML ... more information. Accession number format Each metadata object is assigned a unique accession number by the archive. The accession numbers can be used to retrieve data and metadata using the EB-Eye search available at the top of all EBI web pages or using the free text search available on the ENA home page. The metadata is then retrieved and displayed through the ENA Browser as in the examples in the above table. Accession numbers assocaited with read data assigned by EBI start with 'ER' and accession numbers assigned by NCBI and DDBJ start with 'SR' and 'DR', respectively. The third letter of the accession number indicates the type of the metadata object. EGA accession numbers start with 'EGA' with the fourth letter indicating the type of the metadata object. The accession numbers have a fixed number of digits after the letters: six for ENA and eleven for EGA. Metadata object Accession prefix Number of digits Example Submission ERA, SRA, DRA 6 ERA000092 Sample ERS, SRS, DRS 6 ERS000081 Study ERP, SRP, DRP 6 ERP000016 Experiment ERX, SRX, DRX 6 ERX000398 Run ERR, SRR, DRR 6 ERR003990 Analysis ERZ, SRZ, DRZ 6 ERZ000001 EGA Submission EGA 11 EGA00001000001 EGA Sample EGAN 11 EGAN00001000001 EGA Study EGAS 11 EGAS00001000001 EGA Experiment EGAX 11 EGAX00001000001 EGA Run EGAR 11 EGAR00001000001 EGA Analysis EGAZ 11 EGAZ00001000001 EGA DAC EGAC 11 EGAC00001000001 EGA Policy EGAP 11 EGAP00001000001 EGA Data Set EGAD 11 EGAD00001000001 Archive generated fastq file format Once made public, data submitted to ENA are available for download using ftp and Aspara. Detailed data download instructions are available here. Currently, both submitted data files and archive generated fastq files are made available for download. The naming and format of the generated fastq files are described below. In general, one fastq file is created for each application read in a run. Please refer to the table below for full details: Number of application reads Fastq Files Description 1 <run_accession>.fastq.gz or <run_accession>_1.fastq.gz For experiments with single application reads only all reads will be made available in one fastq file. 2 <run_accession>_1.fastq.gz <run_accession>_2.fastq.gz <run_accession>.fastq.gz For paired experiments with two application reads reads will be made available in 1-3 fastq files. If a paired experiment is submitted with both application reads then the first reads will be in <run accession>_1.fastq.gz file, the second reads will be in <run accession>_2.fastq.gz, and any unpaired reads will be in <run accession>.fastq.gz file. In case a paired experiment is submitted containing only unpaired reads then only a single file will be created: <run accession>.fastq.gz. > 2 <run_accession>_N.fastq.gz For experiments with more than two application reads (e.g. Complete Genomics or strobed PacBio) one fastq file is created for each application read, however, no empty fastq files are created. The fastq file format is: @<run accession>.<spot index>[ <spot name>\\[/<read index>\\]] <bases> + <phred qualities, ASCII encoded starting with '!' (33)> Field Description <run accession> The Run accession. A spot is identified uniquely by the combination of the Run accession and the spot index. <spot index> A positive integer assigned to the spots in the order in which they appear in the run. A spot is identified uniquely by the combination of the Run accession and the spot index. <spot name> The spot name as it was provided by the submitter. In cases where the read name is missing or was removed by the archive this field is not present. <read index> A positive integer assigned to the application reads in the order in which they appear in the spot: /1 for first application read and /2 for the second application read. In cases where the read name is missing or was removed by the archive this field is not present. Examples Single layout: @ERR000017.1 IL6_554:7:1:249:322 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + ??????????????????????????????>>>>>> Paired (first read): @ERR005143.1 ID49_20708_20H04AAXX_R1:7:1:41:356/1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh Paired (second read): @ERR005143.1 ID49_20708_20H04AAXX_R1:7:1:41:356/2 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh Single layout without read names: @ERR000017.1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + ??????????????????????????????>>>>>> Paired without read names (first read): @ERR005143.1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh Paired without read names (second read): @ERR005143.1 AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA + hhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh SOLiD color: The first base is included before the SOLiD colors. @ERR000451.1 VAB_S0103_20080915_542_14_17_70_F3 T33023230203102103223330020300233001 + T<.6353&:#\$1%&(--27*%&%, Submit & Update Data formats Accession numbers Sequences Reads Read file formats XML 1.5 XML 1.4 XML 1.3 XML 1.2 XML 1.1 XML 1.0 Library strategy Trace Projects Taxonomy Uploading data files Reads Sequences Genome assemblies Taxonomy Sample checklists Environmental Epigenomic Species BARCODE Metadata model Register submission account Programmatic XML submissions Programmatic tabulated submissions Popular Submit and update Sequence submissions Genome assembly submissions Submitting environmental sequences Citing ENA data Rest URLs for data retrieval Rest URLs to search ENA Latest ENA news 09 Dec 2015: ENA Release 126 Release 126 of ENA's assembled/annotated sequences now available 02 Nov 2015: Change to Globus endpoint for public ENA data The Globus endpoint for public ENA data is changing from ebi#ena to ebi#public ('ena' subfolder). 23 Sep 2015: ENA Release 125 Release 125 of ENA's assembled/annotated sequences now available EMBL European Bioinformatics Institute News Brochures Contact us Intranet Services By topic By name (A-Z) Help & Support Research Overview Publications Research groups Postdocs & PhDs Training Overview Train at EBI Train outside EBI Train online Contact organisers Industry Overview Members Area Workshops SME Forum Contact Industry programme About us Overview Leadership Funding Background Collaboration Jobs People & groups News Events Visit us Contact us EMBL-EBI, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire, CB10 1SD, UK +44 (0)1223 49 44 44 Copyright © EMBL-EBI 2015 | EBI is an outstation of the European Molecular Biology Laboratory | Terms of use OK This website uses cookies. By continuing to browse this site, you are agreeing to the use of our site cookies. To find out more, see our Terms of Use.`; let m; while ((m = regex.exec(str)) !== null) { // This is necessary to avoid infinite loops with zero-width matches if (m.index === regex.lastIndex) { regex.lastIndex++; } // The result can be accessed through the `m`-variable. m.forEach((match, groupIndex) => { console.log(`Found match, group ${groupIndex}: ${match}`); }); }

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 JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions