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Lookbehind in JS regular expressions

- OTHER

The positive lookbehind ((?<= )) and negative lookbehind ((?<! )) zero-width assertions in JavaScript regular expressions can be used to ensure a pattern is preceded by another pattern.

IE

  1. 5.5 - 10: Not supported
  2. 11: Not supported

Edge

  1. 12 - 18: Not supported
  2. 79 - 96: Supported
  3. 97: Supported

Firefox

  1. 2 - 77: Not supported
  2. 78 - 95: Supported
  3. 96: Supported
  4. 97 - 98: Supported

Chrome

  1. 4 - 61: Not supported
  2. 62 - 96: Supported
  3. 97: Supported
  4. 98 - 100: Supported

Safari

  1. 3.1 - 15.1: Not supported
  2. 15.2: Not supported
  3. TP: Not supported

Opera

  1. 9 - 48: Not supported
  2. 49 - 81: Supported
  3. 82: Supported

Safari on iOS

  1. 3.2 - 15.1: Not supported
  2. 15.2: Not supported

Opera Mini

  1. all: Not supported

Android Browser

  1. 2.1 - 4.4.4: Not supported
  2. 97: Supported

Opera Mobile

  1. 10 - 12.1: Not supported
  2. 64: Supported

Chrome for Android

  1. 97: Supported

Firefox for Android

  1. 95: Supported

UC Browser for Android

  1. 12.12: Supported

Samsung Internet

  1. 4 - 7.4: Not supported
  2. 8.2 - 15.0: Supported
  3. 16.0: Supported

QQ Browser

  1. 10.4: Supported

Baidu Browser

  1. 7.12: Not supported

KaiOS Browser

  1. 2.5: Not supported
Resources:
Blog post on lookbehind assertions
Safari implementation bug
Firefox implementation bug
MDN: Regular Expressions Assertions