Regex – What flavor of Regex does Visual Studio Code use

regexreplacevisual-studio-code

Trying to search-replace in Visual Studio Code, I find that its Regex flavor is different from full Visual Studio. Specifically, I try to declare a named group with string (?<p>[\w]+) which works in Visual Studio but not in Visual Studio Code. It'll complain with the error Invalid group.

Apart from solving this specific issue, I'm looking for information about the flavor of Regexes in Visual Studio Code and where to find documentation about it, so I can help myself with any other questions I might stumble upon.

Full Visual Studio uses .NET Regular Expressions as documented here. This link is mentioned as the documentation for VS Code elsewhere on Stackoverflow, but it's not.

Best Answer

Rust Regex in the Find/Replace in Files Sidebar

Rob Lourens of MSFT wrote that the file search uses Rust regex. The Rust language documentation describes the syntax.

JavaScript Regex in the Find/Replace in File Widget

Alexandru Dima of MSFT wrote that the find widget uses JavaScript regex. As Wicktor commented, ECMAScript 5's documentation describes the syntax. So does the MDN JavaScript Regular Expression Guide.

Test the Difference

The find in files sidebar does not support (?=foobar) whereas the find in file widget does support that lookahead syntax.

Regarding Find/Replace with Groups

To find/replace with groups, use parentheses () to group and $1, $2, $3, $n to replace.

Here is an example.

Before:

After:

Related Solutions

Jquery – how to change div text after form submit

The # symbol identifies the ID of the element. Use .text() to set the inner text.

$('div#printdirec').text('tttt');

Reset a char *array[size] contents

You have

char *array[size];

That makes array an array of pointers. Specifically, array is an array of size pointers. Each element in the array (array[0] to array[size-1]) is of type char *.

I think it would help if you understood how array works:

+-------+-------+-------+-------+
|  [0]  |  [1]  |  [2]  |  [3]  |
+-------+-------+-------+-------+
    |       |       |       |
    |       |       |       |
    |       |       |       |
    v       v       v       v

Each of the boxes above represents a pointer, and the arrows are where they are pointing to. The storage for them is not yet assigned to, so they are just "out there", pointing nowhere useful. You can either create memory for them (malloc() etc., in C, new[] in C++), or you can point them to some existing location.

You say:

...put some strings in it. If I assign something again to them, they don't replace the previous contents but they keep on appending on the previous contents. How do I correctly clear/reset all of its contents?

It is not clear how you are putting "strings in it". Do you mean you are storing strings in array[0]..array[size-1]? How? Are you assigning literal strings to them? Something like:

array[0] = "String";

If you are doing that, then, you can reassign to the pointers and the strings wouldn't append. In other words, if later in your program you do:

array[0] = "Another string";

you are reassigning the pointer array[0] to point to "Another string", and thus you're not appending.

So, in short, we need to see more code, and you may need to understand pointers and arrays better.

Edit: Based upon your edit, the pointers myMainArr[i] (for i=0 to i=3), do get reassigned to the corresponding elements from myArrOne or myArrOne (not a typo!), depending upon the contents of action. So, if you printed them (for example, printf("%s\n", myMainArr[0]);), you shouldn't see any strings being appended. Also, myMainArr is local to your function function, so it gets destroyed when your function returns. (Incidentally, your choice of the names array for an array and function for a function make it harder to be unambiguous when answering the question!)

If you are having a problem, please post a complete, minimal, compilable code that shows the problem.