RegEx in javascript freezes the screen

Asked Jan 22 '19 at 11:31

Active Jan 22 '19 at 11:31

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regEx in javascript freezes the screen. i have code for validating file name and when some extra characters are added like '{' or '[' the screen freezes

var acceptFileTypes = /^([a-z\s*\_*\-*\(*\)*\,*\'*\;*\&*\$*\#*\@*\.*\!*0-9]+)+\.(xlsx|ppt|pptx|doc|docx|pdf|tiff|tif|msg)$/i;  

var fileName="business business business business business business return preparation business [.docx"

acceptFileTypes.test(fileName)

asked Jan 22 '19 at 11:31

Ireal

5

Classic catastrophic backtracking, you have `(a+)+` inside the pattern. – Wiktor Stribiżew Jan 22 '19 at 11:32
Avoid writing regular expressions if you don't have any clue in what they are. – revo Jan 22 '19 at 11:44
@WiktorStribiżew thank you for highlighting whats wrong. will have to read about it – Ireal Jan 22 '19 at 11:46
@revo :). i'm stuck with supporting legacy application. will correct this one. [not my code] – Ireal Jan 22 '19 at 11:47

RegEx in javascript freezes the screen

0 Answers0