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
No Match

/
/
gm

Test String

Code Generator

Language

Generated Code

const regex = /\.java:\d+\)([\r\n]+)\s\S+/gm; // Alternative syntax using RegExp constructor // const regex = new RegExp('\\.java:\\d+\\)([\\r\\n]+)\\s\\S+', 'gm') const str = `Total threads: 434 on 2018-04-29T17-00-03+0800 Name CPU Time (ms) User Time (ms) Id State IPC Parameter Sending Thread #868 0 0 17782 TIMED_WAITING waiting on java.util.concurrent.SynchronousQueue\$TransferStack@4d974d1c at sun.misc.Unsafe.park(Native Method) at java.util.concurrent.locks.LockSupport.parkNanos(LockSupport.java:215) at java.util.concurrent.SynchronousQueue\$TransferStack.awaitFulfill(SynchronousQueue.java:460) at java.util.concurrent.SynchronousQueue\$TransferStack.transfer(SynchronousQueue.java:362) at java.util.concurrent.SynchronousQueue.poll(SynchronousQueue.java:941) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1066) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor\$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) IPC Client (2006835220) connection to abcd.com/10.21.216.71:8020 from hdfs 0 0 17781 TIMED_WAITING waiting on org.apache.hadoop.ipc.Client\$Connection@5be22c7a at java.lang.Object.wait(Native Method) at org.apache.hadoop.ipc.Client\$Connection.waitForWork(Client.java:931) at org.apache.hadoop.ipc.Client\$Connection.run(Client.java:976) 1306724746@qtp-695248316-10273 29 10 17780 TIMED_WAITING waiting on org.mortbay.thread.QueuedThreadPool\$PoolThread@4de3098a at java.lang.Object.wait(Native Method) at org.mortbay.thread.QueuedThreadPool\$PoolThread.run(QueuedThreadPool.java:626) 2125946201@qtp-695248316-10271 40 20 17776 TIMED_WAITING waiting on org.mortbay.thread.QueuedThreadPool\$PoolThread@7eb75d59 at java.lang.Object.wait(Native Method) at org.mortbay.thread.QueuedThreadPool\$PoolThread.run(QueuedThreadPool.java:626) 1805988475@qtp-695248316-10269 133 70 17772 TIMED_WAITING waiting on org.mortbay.thread.QueuedThreadPool\$PoolThread@6ba5327b at java.lang.Object.wait(Native Method) at org.mortbay.thread.QueuedThreadPool\$PoolThread.run(QueuedThreadPool.java:626) 402769840@qtp-695248316-10266 161 90 17766 TIMED_WAITING waiting on org.mortbay.thread.QueuedThreadPool\$PoolThread@1801c7b0 at java.lang.Object.wait(Native Method) at org.mortbay.thread.QueuedThreadPool\$PoolThread.run(QueuedThreadPool.java:626) FastExecutor-3-60 1 0 17747 WAITING waiting on java.util.concurrent.locks.AbstractQueuedSynchronizer\$ConditionObject@476f266c at sun.misc.Unsafe.park(Native Method) at java.util.concurrent.locks.LockSupport.park(LockSupport.java:175) at java.util.concurrent.locks.AbstractQueuedSynchronizer\$ConditionObject.await(AbstractQueuedSynchronizer.java:2039) at java.util.concurrent.LinkedBlockingQueue.take(LinkedBlockingQueue.java:442) at java.util.concurrent.ThreadPoolExecutor.getTask(ThreadPoolExecutor.java:1067) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1127) at java.util.concurrent.ThreadPoolExecutor\$Worker.run(ThreadPoolExecutor.java:617) at com.xyz.shadow.io.netty.util.concurrent.DefaultThreadFactory\$DefaultRunnableDecorator.run(DefaultThreadFactory.java:145) at java.lang.Thread.run(Thread.java:745)`; // Reset `lastIndex` if this regex is defined globally // regex.lastIndex = 0; 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