Javascript正则表达式（？i）^ inf

Question

I want to know what this regular expression refers.

(?i)^inf

With examples

Answer 1

It's easy to figure : type /(?i)^inf/ in the console.

Conclusion : it's an invalid regular expression in JavaScript.

But I guess you saw this regex in another language. If you want to use flags in JavaScript regular expressions , the syntax is different :

/^inf/i

What it means is : a string starting with "inf" , with case insensitive matching.

Answer 2

Not Valid in JavaScript

JavaScript doesn't support inline modifiers such as (?i) (see below). This regex is not proper JavaScript syntax.

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In many other flavors... Any string that starts with inf , case-insensitive.

In .NET, Java, PCRE, Perl, Python, Ruby and a number of other engines, (?i) turns on case-insensitivity.

Sample matches

infact
inFahrenheit
INF
INFO
INfine

How it Works

• (?i) turns on case-insensitivity mode
• The ^ anchor asserts that we are at the beginning of the string
• inf matches literal characters

Answer 3

I don't know it supports in Java-script or not.

But i got to know (?i) means case-insensitive

Example:-

(?i)integer matches Integer, inTeger, etc,.