Develop Reference

Regex simply not working in IE 8, 9 and 10

Here is our text to replace:
<IMG src="https://domain.com/images/siteheader.jpg">
Using javascript .replace, we try to replace with blank space using the following:
.replace ("/<A href=\"http:\/\/domain.com\"><IMG src=\"https:\/\/domain.com\/images\/siteheader.jpg\"><\/A>/i"," ");
In all other browsers this seems to work, but not in IE. I even tried using this online regex validator: http://www.online-toolz.com/tools/regexp-editor.php and it says it's valid. Kind of stumped. Is IE doing something out of the norm?

You either use a string (the literal form of which looks like "...") or a regular expression (the literal form of which looks like /.../) with replace. You're trying to do both simultaneously. Remove the quotes:
.replace (/<A href="http:\/\/domain.com"><IMG src="https:\/\/domain.com\/images\/siteheader.jpg"><\/A>/i, " ");
When you use a string, it's just matched literally, no regular expression processing is done.
I haven't validated the entire contents of the regex, just removed the surrounding " and removed the \ in front of the embedded ".

Regexes are literals and should not have quotes around them:
.replace(/your regex here/,'replacement')
That being said, where is the text coming from? If it's coming from .innerHTML, browsers may return a string that is different from what you literally have in the source (for instance, attribute names may be uppercased, or the attributes themselves swapped. I believe older versions of IE strip out quotes around single-word attribute values, which would also mess with your regex.
In short, you should not use a regex for this. You could try this instead:
var toRemove = document.querySelector("a[href='http://domain.com']"),
parent = toRemove.parentNode;
parent.removeChild(toRemove);

Converting special characters in c# string to html special characters

I am using .Net:
fulltext = File.ReadAllText(#location);
to read text anyfile content at given locatin.
I got result as:
fulltext="# vdk10.syx\t1.1 - 3/15/94\r# #(#)Copyright (C) 1987-1993 Verity, Inc.\r#\r# Synonym-list Database Descriptor\r#\r$control: 1\rdescriptor:\r{\r data-table: syu\r {\r worm:\tTHDSTAMP\t\tdate\r worm:\tQPARSER\t\t\ttext\r\t/_hexdata = yes\r varwidth:\tWORD\t\tsyv\r fixwidth:\tEXPLEN\t\t\t2 unsigned-integer\r varwidth:\tEXPLIST\t\tsyx\r\t/_hexdata = yes\r }\r data-table: syw\r {\r varwidth:\tSYNONYMS\tsyz\r }\r}\r\r ";
Now, I want this fulltext to be displayed in html page so that special characters are recognized in html properly. For examples: \r should be replaced by line break tag
so that they are properly formatted in html page display.
Is there any .net class to do this? I am looking for universal method since i am reading file and I can have any special characters. Thanks in advance for help or just direction.

You're trying to solve two problems:
Ensure special characters are properly encoded
Pretty-print your text
Solve them in this order:
First, encode the text, by importing the System.Web namespace and using HttpUtility (asked on StackOverflow). Use the result in step 2.
Pretty-printing is trickier, depending on the amount of pretty-printing that you want. Here are a few approaches, in increasing order of difficulty:
Put the text in a pre element. This should preserve newlines, tabs, spaces. You can still adjust the font used using CSS if you first slap a CSS class on the pre.
Replace all \r, \r\n and remaining \n with <br/>.
Study the structure of your text, parse it according to this structure, and provide specific tags in specific contexts. For example, the tab characters in your example may be indicative of a list of items. HTML provides the ol and ul elements for lists. Similarly, consecutive line breaks may indicate paragraphs, for which HTML provides the well known p element.

Thanks Everyone here for your valuable comment. I solved my formatting problem in client side with following code.
document.getElementById('textView').innerText = fulltext;
Here textview is the div where i want to display my fulltext . I don't think i need to replace special characters in string fulltext. I output as shown in the figure.

JavaScript automatically converts some special characters

I need to extract a HTML-Substring with JS which is position dependent. I store special characters HTML-encoded.
For example:
HTML
<div id="test"><p>lösen & grüßen</p></div>​
Text
lösen & grüßen
My problem lies in the JS-part, for example when I try to extract the fragment
lö, which has the HTML-dependent starting position of 3 and the end position of 9 inside the <div> block. JS seems to convert some special characters internally so that the count from 3 to 9 is wrongly interpreted as "lösen " and not "lö". Other special characters like the & are not affected by this.
So my question is, if someone knows why JS is behaving in that way? Characters like ä or ö are being converted while characters like & or are plain. Is there any possibility to avoid this conversion?
I've set up a fiddle to demonstrate this: JSFiddle
Thanks for any help!
EDIT:
Maybe I've explained it a bit confusing, sorry for that. What I want is the HTML:
<p>lösen & grüßen</p> .
Every special character should be unconverted, except the HTML-Tags. Like in the HTML above.
But JS converts the ö or ü into ö or ü automatically, what I need to avoid.

That's because the browser (and not JavaScript) turns entities that don't need to be escaped in HTML into their respective Unicode characters (e.g. it skips &, < and >).
So by the time you inspect .innerHTML, it no longer contains exactly what was in the original page source; you could reverse this process, but it involves the full map of character <-> entity pairs which is just not practical.

If i understand you correctly, then try use innerHTML or .html('your html code') for jQuery on the target element

Remove a long dash from a string in JavaScript?

I've come across an error in my web app that I'm not sure how to fix.
Text boxes are sending me the long dash as part of their content (you know, the special long dash that MS Word automatically inserts sometimes). However, I can't find a way to replace it; since if I try to copy that character and put it into a JavaScript str.replace statement, it doesn't render right and it breaks the script.
How can I fix this?
The specific character that's killing it is —.
Also, if it helps, I'm passing the value as a GET parameter, and then encoding it in XML and sending it to a server.

This code might help:
text = text.replace(/\u2013|\u2014/g, "-");
It replaces all – (–) and — (—) symbols with simple dashes (-).
DEMO: http://jsfiddle.net/F953H/

That character is call an Em Dash. You can replace it like so:
str.replace('\u2014', '');​​​​​​​​​​
Here is an example Fiddle: http://jsfiddle.net/x67Ph/
The \u2014 is called a unicode escape sequence. These allow to to specify a unicode character by its code. 2014 happens to be the Em Dash.

There are three unicode long-ish dashes you need to worry about: http://en.wikipedia.org/wiki/Dash
You can replace unicode characters directly by using the unicode escape:
'—my string'.replace( /[\u2012\u2013\u2014\u2015]/g, '' )

There may be more characters behaving like this, and you may want to reuse them in html later. A more generic way to to deal with it could be to replace all 'extended characters' with their html encoded equivalent. You could do that Like this:
[yourstring].replace(/[\u0080-\uC350]/g,
function(a) {
return '&#'+a.charCodeAt(0)+';';
}
);

With the ECMAScript 2018 standard, JavaScript RegExp now supports Unicode property (or, category) classes. One of them, \p{Dash}, matches any Unicode character points that are dashes:
/\p{Dash}/gu
In ES5, the equivalent expression is:
/[-\u058A\u05BE\u1400\u1806\u2010-\u2015\u2053\u207B\u208B\u2212\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u2E5D\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]|\uD803\uDEAD/g
See the Unicode Utilities reference.
Here are some JavaScript examples:
const text = "Dashes: \uFF0D\uFE63\u058A\u1400\u1806\u2010-\u2013\uFE32\u2014\uFE58\uFE31\u2015\u2E3A\u2E3B\u2053\u2E17\u2E40\u2E5D\u301C\u30A0\u2E1A\u05BE\u2212\u207B\u208B\u3030𐺭";
const es5_dash_regex = /[-\u058A\u05BE\u1400\u1806\u2010-\u2015\u2053\u207B\u208B\u2212\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u2E5D\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]|\uD803\uDEAD/g;
console.log(text.replace(es5_dash_regex, '-')); // Normalize each dash to ASCII hyphen
// => Dashes: ----------------------------
To match one or more dashes and replace with a single char (or remove in one go):
/\p{Dash}+/gu
/(?:[-\u058A\u05BE\u1400\u1806\u2010-\u2015\u2053\u207B\u208B\u2212\u2E17\u2E1A\u2E3A\u2E3B\u2E40\u2E5D\u301C\u3030\u30A0\uFE31\uFE32\uFE58\uFE63\uFF0D]|\uD803\uDEAD)+/g

Basic Regex to remove any space

I'm looking for a basic regex that removes any space. I want to use it for ZIP code.
Some people insert space after, before or in between the ZIP code.
I'm using /^\d{5}$/ now. I want to expand it to include space removal.
How can this be improved?

(I'm considering you want to remove spaces in your string, not verifying if it is valid even with spaces)
You can substitute one or more spaces (globally)
/\s+/g
by nothing.
zip.replace(/\s+/g, "");
Example in my browser's JS console:
> " 02 1 3 4".replace(/\s+/g, "");
"02134"

Here's a regex you can use instead of your current one to ignore any and all spaces.
/^(\s*\d){5}\s*$/

If you're sanitizing a form input or something, it's probably easiest to use:
zip = zip.replace(/\D/g,'');
you can then validate without a regex, just use the .length property on String.
if(zip.length != 5) alert('failed!');