Skip to content
Related Articles

Related Articles

JavaScript SyntaxError – Invalid regular expression flag “x”
  • Last Updated : 24 Jul, 2020

This JavaScript exception invalid regular expression flag occurs if the flags, written after the second slash in RegExp literal, are not from either of (g, i, m, s, u, or y).

Message:

SyntaxError: Syntax error in regular expression (Edge) 
SyntaxError: invalid regular expression flag "x" (Firefox)
SyntaxError: Invalid regular expression flags (Chrome)

Error Type:

SyntaxError

Cause for Error: Somewhere in the code, There are regular expression flags that are not valid.

Example 1: This example has valid RegExp flags.



HTML

filter_none

edit
close

play_arrow

link
brightness_4
code

<!DOCTYPE html>
<html>
<head>
    <title>Syntax Error</title>
</head>
<body>
    <script>
        var patt = /GeeksforGeeks/i;
        var str = 'This is GeeksforGeeks';
        document.write(str.match(patt));
    </script>
</body>
</html>

chevron_right


Output:

GeeksForGeeks

Example 2: In this example, After second slash ‘GFG’ is used as a flag which is invalid.

HTML

filter_none

edit
close

play_arrow

link
brightness_4
code

<!DOCTYPE html>
<html>
<head>
    <title>Syntax Error</title>
</head>
<body>
    <script>
        var patt = /Geek/GFG;
        var str = 'This is GeeksforGeeks';
        document.write(str.match(patt));
    </script>
</body>
</html>

chevron_right


Output(in console):

SyntaxError: Invalid regular expression flags

full-stack-img

My Personal Notes arrow_drop_up
Recommended Articles
Page :