Develop Reference

How to replace numbers with an empty char

i need to replace phone number in string on \n new line.
My string: Jhony Jhons,jhon#gmail.com,380967574366
I tried this:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366'
var regex = /[0-9]/g;
var rec = str.trim().replace(regex, '\n').split(','); //Jhony Jhons,jhon#gmail.com,
Number replace on \n but after using e-mail extra comma is in the string need to remove it.
Finally my string should look like this:
Jhony Jhons,jhon#gmail.com\n

You can try this:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366';
var regex = /,[0-9]+/g;
str.replace(regex, '\n');
The snippet above may output what you want, i.e. Jhony Jhons,jhon#gmail.com\n

There's a lot of ways to that, and this is so easy, so try this simple answer:-
var str = 'Jhony Jhons,jhon#gmail.com,380967574366';
var splitted = str.split(","); //split them by comma
splitted.pop(); //removes the last element
var rec = splitted.join() + '\n'; //join them

You need a regex to select the complete phone number and also the preceding comma. Your current regex selects each digit and replaces each one with an "\n", resulting in a lot of "\n" in the result. Also the regex does not match the comma.
Use the following regex:
var str = 'Jhony Jhons,jhon#gmail.com,380967574366'
var regex = /,[0-9]+$/;
// it replaces all consecutive digits with the condition at least one digit exists (the "[0-9]+" part)
// placed at the end of the string (the "$" part)
// and also the digits must be preceded by a comma (the "," part in the beginning);
// also no need for global flag (/g) because of the $ symbol (the end of the string) which can be matched only once
var rec = str.trim().replace(regex, '\n'); //the result will be this string: Jhony Jhons,jhon#gmail.com\n

var str = "Jhony Jhons,jhon#gmail.com,380967574366";
var result = str.replace(/,\d+/g,'\\n');
console.log(result)

Replace whitespace whitespace and put string a new array

I would like to remove all whitespace and special char and put ever nummer in a new array like this: var numbers = ['17','9','18','4A'];
This what i am doing to remove whitespace and special character, but how do put clean it more and put in a array?
var str = "(17 - 9), (18 - 4A)"
str.replace(/[()-\s]/g, '');
output: "179,184A"

Don't think of it as removing the extra stuff and just think of it as grabbing what you want.
var input = "(17 - 9), (18 - 4A)";
// Match anything which has one or more numbers or letters in a row
var pattern = /[\da-z]+/gi;
var output = input.match(pattern);
console.log(output);

You can use split method, it returns an array:
var myArray = str.replace(/[()-\s]/g, '').split(',');

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

Get all characters except hyphen and brackets from string using javascript regex

I have a string like this:
var myString = "MyString-[ADDAAD]-isGreat";
I want to extract this string into 3 parts:
var stringOne = "MyString-";
var stringTwo = "ADDAAD";
var stringThree = "-isGreat";
I know how to get the string between the two square brackets:
var matches = patternString.match(/\[(.*?)\]/);
now matches[1] contains ADDAAD
But how can I get the other two parts?

Select every character except -, [ and ] using bottom regex.
var myString = "MyString-[ADDAAD]-isGreat";
var parts = myString.match(/[^-\[\]]+/g);
console.log(parts);
So if you want to store values in custom variable, use bottom code
var stringOne = parts[0];
var stringTwo = parts[1];
var stringThree = parts[2];

You may split the string with your regex. Note that all the capturing group contents will be also part of the resulting array. To avoid empty items, you may add .filter(Boolean) after split().
See a JS demo below:
var myString = "MyString-[ADDAAD]-isGreat";
console.log(myString.split(/\[(.*?)]/).filter(Boolean));
console.log("s1-[s2]".split(/\[(.*?)]/).filter(Boolean));
Note you do not have to escape a ] used outside character classes, it is always parsed as a literal closing bracket if there is no corresponding [ before it.

How to strip last element of dash delimited string in Javascript

I have string delimited with dashes like:
x#-ls-foobar-takemeoff-
How can I remove takemeoff- using javascript where takemeoff- can be any amount of characters ending in a dash?

var str = "x#-ls-foobar-takemeoff-";
var newStr = str.replace(/[^-]+-$/,"");
Basic regular expression says
[^-]+ <-- Match any characters that is not a dash
- <-- Match a dash character
$ <-- Match the end of a string

If you have a string str, you can do the following:
str = str.substr(0, str.lastIndexOf("-", str.length - 2));

Using substr() and lastIndexOf():
var myStr = "x#-ls-foobar-takemeoff-";
myStr = myStr.substr(0, myStr.length-1); // remove the trailing -
var lastDash = myStr.lastIndexOf('-'); // find the last -
myStr = myStr.substr(0, lastDash);
alert(myStr);
Outputs:
x#-ls-foobar
jsFiddle here.