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Regex catch from the hash sign "#" to the next white space

I have a script line this :
#type1 this is the text of the note
I've tried this bu didn't workout for me :
^\#([^\s]+)
I watch to catch type in other words I to get whats between the hash sign "#" and the next white space, excluding the hash "#" sign, and the string that I want to catch is alphanumeric string.

With the regex functionality provided by Javascript:
exec_result = /#(\w*)/.exec('#whatever string comes here');
I believe exec_result[1] should be the string you want.
The return value of exec() method could be found over here:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp/exec

You're really close:
/^\#(\w+)\s/
The \w matches any letters or numbers (and underscores too). And the space should be outside the matching group since I guess you don't want to capture it.

To get an alphanumeric match (which will get you type1), instead of the negated character class [^\s] which matches not a whitespace character, you could use a character class and specify what you want to match like [A-Za-z0-9].
Then use a negative lookahead to assert what is on the right is not a non-whitespace char:
^#([A-Za-z0-9]+)(?!\S)
Regex demo
Your match is in the first capturing group. Note that you don't have to escape the \#
For example using the case insensitive flag /i
const regex = /^#([A-Za-z0-9]+)(?!\S)/i;
const str = `#type1 this is the text of the note`;
console.log(str.match(regex)[1]);
If you only want to match type, you might use:
^#([a-z]+)[a-z0-9]*(?!\S)
Regex demo
const regex = /^#([a-z]+)[a-z0-9]*(?!\S)/i;
const str = `#type1 this is the text of the note`;
console.log(str.match(regex)[1]);

I've figured it out.
/^\#([^\s]+)+(.*)$/

Regex - How do I match all groups of characters that both do and do not match a pattern?

I'm trying to match groups of characters that both match and don't match the pattern /\*\d*\*/g. For example, if my string is:
"*96* is *5* and not *547*."
I want my matches to be "*96*", " is ", "*5*", " and not ", "*547*" and ".".
All the answers I've seen have involved negative lookaheads but I just can't get them to work correctly.

Instead of matching, you could use your pattern inside a capturing group to keep the delimiters (\*\d*\*) and use split :
let str = "*96* is *5* and not *547*.";
console.log(str.split(/(\*\d*\*)/g).filter(Boolean))

I know you asked for a straight regex answer, but what about using split with a regex separator? It will then put where the string has split in an array.
var test = "*96* is *5* and not *547*.";
var splits = test.split(/\*\d*\*/g);
console.log(splits);

Regex keeps finding character I want matched along with previous character

I have the following regex in javascript for a split operation since I can't do a negative look behind to find any delimiters , in a string that is not proceeded by one or more escape characters of \.
[^\\],
The regex works fine for finding where the commas not proceeded by \ are, but also finds the character that proceeds the comma as a match and thus splits the string incorrectly.
For example if I had the string
hello\,there,are
The result would be that e, matches my regex and not just ,. Making the split string array read
[hello\,ther] [are]
Why does the regex I am using keep finding the comma and the proceeding character instead of only matching the comma?

You cannot use split here because you'd need a lookbehind that JS regex does not support. Use a match with appropriate regex. Like the one below:
/(?:[^\\,]|\\.)+/g
See the regex demo.
The pattern matches 1 or more (+) sequences of any char other than , and \ ([^\\,]) or (|) any escaped character (excluding linebreak chars) with \\.
JS demo:
var regex = /(?:[^\\,]|\\.)+/g;
var str = "hello\\,there,are";
var res = str.match(regex);
console.log(res);

JS String: Add whitespace between numbers and letters

i need a regular expression or any other method to add whitespaces between numbers and letters in a string.
Example:
"E2356" => "E 2356"
"E123-F456" => "E 123-F 456"
I already found a regular expression capable of it but it is not possible with Javascript:
(?<=[^0-9])(?=[0-9])
Thanks!

Instead of a look-behind, just match the non-digit:
[^0-9](?=[0-9])
And replace with "$& ".
The [^0-9] subpattern will match 1 character that is not a digit that can be referenced with $& (the whole matched text) in the replacement pattern. (?=[0-9]) lookahead will make sure there is a digit right after it.
See demo
var re = /[^0-9](?=[0-9])/g;
var str = 'E2356<br/>E123-F456';
var result = str.replace(re, '$& ');
document.write(result);

Match the two-character sequence of letter followed by number, with capture groups for both the letter and number, then use String#replace with the $1 and $2 placeholders to refer to the content of the capture groups, with a space in between.
str.replace(/([^0-9])([0-9])/g, '$1 $2')
^^$1^^ ^^$2^
The g flag ensures all occurrences are replaced, of course.

Use String#replace:
'E123-F456'.replace(/([A-Z])(\d)/g, '$1 $2')
// >>> "E 123-F 456"
$1 and $2 are the captured groups from the regex and are separated by a space. The expression assumes you only have uppercase characters. Remember to add the g flag to your expression to replace every occurrence.

You cannot format a string using regex.
Regex helps you validate that whether a certain string follow the language described by expression.
Regex helps you capture certain parts of the string in different variables and then format them as you want to get the desired output.
So I would suggest you do something like this :
var data = "E2304" ;
var regex = ([^0-9])([0-9]*)/g ;
data.replace(/regex, '$1 $2') ;

Try below code
var test = "E123-F456".match(/[a-zA-Z]+|[0-9]+/g);
console.log(test.join(' '));
fiddle http://jsfiddle.net/anandgh/h2g8cnha/

Javascript reg exp not right

Here is a string str = '.js("aaa").js("bbb").js("ccc")', I want to write a regular expression to return an Array like this:
[aaa, bbb, ccc];
My regular expression is:
var jsReg = /.js\(['"](.*)['"]\)/g;
var jsAssets = [];
var js;
while ((js = jsReg.exec(find)) !== null) {
jsAssets.push(js[1]);
}
But the jsAssets result is
[""aaa").js("bbb").js("ccc""]
What's wrong with this regular expression?

Use the lazy version of .*:
/\.js\(['"](.*?)['"]\)/g
^
And it would be better if you escape the first dot.
This will match the least number of characters until the next quote.
jsfiddle demo
If you want to allow escaped quotes, use something like this:
/\.js\(['"]((?:\\['"]|[^"])+)['"]\)/g
regex101 demo

I believe it can be done in one-liner with replace and match method calls:
var str = '.js("aaa").js("bbb").js("ccc")';
str.replace(/[^(]*\("([^"]*)"\)[^(]*/g, '$1,').match(/[^,]+/g);
//=> ["aaa", "bbb", "ccc"]

The problem is that you are using .*. That will match any character. You'll have to be a bit more specific with what you are trying to capture.
If it will only ever be word characters you could use \w which matches any word character. This includes [a-zA-Z0-9_]: uppercase, lowercase, numbers and an underscore.
So your regex would look something like this :
var jsReg = /js\(['"](\w*)['"]\)/g;

In
/.js\(['"](.*)['"]\)/g
matches as much as possible, and does not capture group 1, so it matches
"aaa").js("bbb").js("ccc"
but given your example input.
Try
/\.js\(('(?:[^\\']|\\.)*'|"(?:[\\"]|\\.)*"))\)/
To break this down,
\. matches a literal dot
\.js\( matches the literal string ".js("
( starts to capture the string.
[^\\']|\\. matches a character other than quote or backslash or an escaped non-line terminator.
(?:[\\']|\\.)* matches the body of a string
'(?:[\\']|\\.)*' matches a single quoted string
(...|...) captures a single quoted or double quoted string
)\) closes the capturing group and matches a literal close parenthesis
The second major problem is your loop.
You're doing a global match repeatedly which makes no sense.
Get rid of the g modifier, and then things should work better.

Try this one - http://jsfiddle.net/UDYAq/
var str = new String('.js("aaa").js("bbb").js("ccc")');
var regex = /\.js\(\"(.*?)\"\){1,}/gi;
var result = [];
result = str.match (regex);
for (i in result) {
result[i] = result[i].match(/\"(.*?)\"/i)[1];
}
console.log (result);

To be sure that matched characters are surrounded by the same quotes:
/\.js\((['"])(.*?)\1\)/g