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Remove string between two variables

I have a string which has some data with a few special characters, Need to remove the data between the desired special char in JavaScript.
The special char would be obtained in a variable.
var desiredChar = "~0~";
And Imagine this to be the Input string:
~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~
So I'm supposed to remove the text in bold.
The desired output is supposed to be-
~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~
I've tried using "Replace" and "Regex", but as the desired character is being passed in a variable and keeps changing I'm facing difficulties.

You can create your own regex based on whatever the bounding character(s) are that contain the text you want removed, and then replace any text that matches that regex with a blank string "".
The JS below should work for your use case (and it should work for multiple occurrences as well):
var originalText = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
var desiredChar = "~0~";
var customRegex = new RegExp(desiredChar + ".*?" + desiredChar, "gi");
var processedText = originalText.replace(customRegex, "");
console.log(processedText);

You can build your regex from the constructor with a string input.
var desiredChar = "~0~";
// use the g flag in your regex if you want to remove all substrings between desiredChar
var myRegex = new Regex(desiredChar + ".*" + desiredChar, 'ig');
var testString = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
testString = testString.replace(myRegex, "");

Given input string you can use .indexOf(), .lastIndexOf() and .slice().
Note, OR character | passed to RegExp constructor should be escaped to avoid RegExp created by passing string interpreting | character as OR | within resulting RegExp passed to .replace().
var desiredChar = "~0~";
var str = "~0~1|0|20170807|45|111.00|~0~~1~1|0|20170807|50|666.00|~1~~2~1|0|20170807|55|111.00|~2~";
var not = str.slice(str.indexOf(desiredChar), str.lastIndexOf(desiredChar) + desiredChar.length);
// escape OR `|`
var res = str.replace(new RegExp(not.replace(/[|]/g, "\\|")), "");
console.log(res)

You can use the RegExp object:
var regexstring = "whatever";
var regexp = new RegExp(regexstring, "gi");
var str = "whateverTest";
var str2 = str.replace(regexp, "other");
document.write(str2);
Then you can construct regexstring in any way you want.
You can read more about it at http://www.regular-expressions.info/javascript.html

how to replace words in string using javascript?

i have a string,
mystr = 'public\uploads\file-1490095922739.jpg';
i want to replace
public\uploads
with " ", so that i just want to extract only file name ie
file-1490095922739.jpg
or like,
\uploads\file-1490095922739.jpg
how can i do this, is there any methods for this in js or can we do it by replace method.
i am performing the following steps,
var imagepath1;
var imagepath = 'public\uploads\file-1490095922739.jpg';
unwantedChar = 'public|uploads';
regExp = new RegExp(unwantedChar , 'gi');
imagepath = imagepath.replace(regExp , '');
imagepath1 = imagepath;
$scope.model.imagepath = imagepath1.replace(/\\/g, "");
please suggest me optimized method.

var input = "public\\uploads\\file-1490095922739.jpg";
var result = input.replace("public\\uploads\\", "");
This is what you're looking for, no need for fancy regexs :). More information about replace can be found here.

Maybe I don't understand the issue - but wouldn't this work?
var mystr = 'public\uploads\file-1490095922739.jpg';
var filename = mystr.replace('public\uploads', '');

If you want to get the part of the string after the last backslash character, you can use this:
var filename = mystr.substr(mystr.lastIndexOf('\\') + 1);
Also note that you need to escape the backslash characters in your test string:
var mystr = 'public\\uploads\\file-1490095922739.jpg';

What about just doing:
var imagepath = 'public\\uploads\\file-1490095922739.jpg';
$scope.model.imagepath = imagepath.replace('public\\uploads\\', '');
instead of using a bunch of unnecessary variables?
This way you're getting the file path, removing public\uploads\ and then setting the file path to $scope.model.imagepath
Note that this will only work if the image file path always matches 'public\uploads\*FILENAME*'.

var url = '/anysource/anypath/myfilename.gif';
var filename = url.slice(url.lastIndexOf('/')+1,url.length);
Search for the last forward slash, and slice the string (+1 because you don't want the slash), with the length of the string to get the filename. This way, you don't have to worry about the path is at all times.

How to remove exact word from a string

If I have a string
TestString = "{Item:ABC, Item:DEF, Item:GHI}";
How can I remove all of the "Item:"s.
I have tried to use
msg = TestString.replace(/[\Item:/&]+/g, "");
but this unfortunately removes all the Is, Ts. Es and M,s from any letters that may follow.
How can I remove the exact text
Thanks!

It should be simple, you can directly create a Regex like /Item:/g,
var TestString = "{Item:ABC, Item:DEF, Item:GHI}";
var msg = TestString.replace(/Item:/g, "");
console.log(msg);

You could use
/Item:/g
for replacing Item:.
The fomer regular expression
/[\Item:/&]+/g
used a character class with single letters instead of a string.
var TestString = "{Item:ABC, Item:DEF, Item:GHI}",
msg = TestString.replace(/Item:/g, "");
console.log(msg);

multiple occurence in a string

I have a string in which I want to replace an occurence which I am not being able to achieve following is the code
var code="user_1/has some text and user_1? also has some text";
newcode=code.replace(/user_1//g,'_');
One more thing if i have to replace a string from another string how to do?
example.
var replacestring="user_1";
var code="user_1/some value here for some user";
var newcode=code.replace(/+replacestring+/g,'_');

/ is a special char thus needs to be escaped with \ before it:
var code = "user_1/has some text and user_1? also has some text";
var newcode = code.replace(/user_1\//g, '_');
alert(newcode);​
Live DEMO
if you want to replace all user_1, use this:
var code = "user_1/has some text and user_1? also has some text";
var newcode = code.replace(/user_1/g, '_');
alert(newcode);​
Live DEMO

Escape the / in the regex using \
newcode=code.replace(/user_1\//g,'_');
For your comment
#Vega I have another confusion. can i use a value in a string to pass
instead of user_1/ for replacement? what would be the syntax?
You can initialize RegEx object like below,
var userName = 'user_1/';
var newcode = code.replace(new RegExp(userName, 'g'), '_');
Read More about RegEx

how to extract string part and ignore number in jquery?

I have a string like foobar1, foobaz2, barbar23, nobar100 I want only foobar, foobaz, barbar, nobar and ignoring the number part.

If you want to strip out things that are digits, a regex can do that for you:
var s = "foobar1";
s = s.replace(/\d/g, "");
alert(s);
// "foobar"
(\d is the regex class for "digit". We're replacing them with nothing.)
Note that as given, it will remove any digit anywhere in the string.

This can be done in JavaScript:
/^[^\d]+/.exec("foobar1")[0]
This will return all characters from the beginning of string until a number is found.

var str = 'foobar1, foobaz2, barbar23, nobar100';
console.log(str.replace(/\d/g, ''));

Find some more information about regular expressions in javascript...
This should do what you want:
var re = /[0-9]*/g;
var newvalue= oldvalue.replace(re,"");
This replaces al numbers in the entire string. If you only want to remove at the end then use this:
var re = /[0-9]*$/g;

I don't know how to do that in JQuery, but in JavaScript you can just use a regular expression string replace.
var yourString = "foobar1, foobaz2, barbar23, nobar100";
var yourStringMinusDigits = yourString.replace(/\d/g,"");