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regex replace jumbles string

This is my console.log:
str : +0-D : replace : Da href="Javascript:PostRating('','|P|622','+0')">+0</a>-D
I have the following function:
function replaceAll_withMatching(str, find, rep, prodId) {
//console.log(str + " : " + find + " : " + rep + " : " + prodId);
var returnString = "";
if (find.toLowerCase() == str.toLowerCase()) {
returnString = rep;
} else {
escfind = "\\" + find ;
var regexp = new RegExp(escfind, "i");
var match = regexp.test(str);
if (match) {
var regAHREF = new RegExp("\\<a", "i");
var AHREFMatch = regAHREF.test(str);
if (AHREFMatch == false) {
str = str.replace(regexp, rep);
str = replaceProductAll(str, PRODUCT_PLACEHOLD, prodId);
} else {
var aTagText = $($.parseHTML(str)).filter('a').text();
if ((find !== aTagText) && (aTagText.indexOf(find) < 0)) {
console.log(regexp);
console.log("str : " + str + " : replace : " + str.replace(regexp, rep));
str = str.replace(regexp, rep);
}
}
}
//console.log(str);
returnString = str;
}
//returnString = replaceProductAll(returnString, PRODUCT_PLACEHOLD, prodId);
return returnString;
}
This function looks for a "<a>" tag, if it doesn't find one then it does the replace. If it does find one it has some conditions that if everything checks out it does another replace.
The string that I'm passing in has been already "parsed" on the +0:
+0-D
In the second pass I'm expecting it to find the "D" in the above string, and then do the following replacement:
D
But as you can see, after the 2nd replace it is jumbling the string and producing malformed HTML
Da href="Javascript:PostRating('','|P|622','+0')">+0</a>-D
More Context:
I have a string that needs to have a replace done on it. This is existing code so I'm not in a position to rework the function.
The original string is: +0-D
This string gets passed into the function below multiple times looking for matches and then if it finds a match it will replace it with the value (also passed in as a parameter).
When the +0-D gets passed in the first time the +0 is matched and a replace is done: +0
Then the next time the string is passed in: +0-D. The function finds the D as a match and it looks like it attempts to do a replace. But it is on this pass that the string gets jumbled.
Ultimately what I'm expecting is this:
+0-D
This is what I'm currently getting after the 2nd attempt:
Da href="Javascript:PostRating('','|P|622','+0')">+0</a>-D
Further Context:
The +0-D is one of many strings this function handles. Some are very simple (i.e. Just +0), others are much more complex.
Question:
Based on the above, what do I need to do to get the regex to not jumble the string?

The problem was in the escfind:
escfind = "\\" + find;
var regexp = new RegExp(escfind,"i");
var match = regexp.test(str);
The first thing I did was in the 2nd replace clause I created a new RegExp to not use the "\\" + find;
if((find !== aTagText) && (aTagText.indexOf(find) < 0)){
try{
var regexp2 = new RegExp(find,"i");
var match2 = regexp2.test(str);
console.log(str.replace(regexp2,rep));
}catch(err){
console.log(err);
}
}
Then my string began to return as expected, however, when I opened it up to all the variations I was getting the Unexpected quantifier error.
Then I found this question - which lead me to escape out my find:
Once I replaced my code with this:
escfind = find.replace(/([*+.?|\\\[\]{}()])/g, '\\$1');
Then I got the output as expected:
<a href='+0'>+0</a>-<a href='D'>D</a>

JavaScript replace all but last whilst preserving original line breaks

I have some code which outputs as follows:
function replaceAllButLast(str, splitRegex, pOld, pNew) {
var parts = str.split(splitRegex)
if (parts.length === 1) return str
return parts.slice(0, -1).join(pNew) + pOld + parts.slice(-1)
}
var str = "fred\r\nfred\r\nfred\r\n"
var desiredResult = replaceAllButLast(str, /(?:\r?\n|\r)/, '\n', '\n+')
console.log(desiredResult)
The result is nearly as desired. However, the code assumes that the regex split operation is splitting on \n and thus is replacing it with \n
However, it may actually be splitting on \r\n (windows - as in the example) or \r (old macs)
Does anyone have some code that would give the same output as the code here BUT will preserve the original line break characters whilst still adding the + after a newline (except on the last line).
I am using pure vanilla JavaScript.
PS I must use the regex /(?:\r?\n|\r)/
PPS There is no need to use .split().

This will keep the last newline as it is but others added a +, see replace
var str = "fred\r\nfred\r\nfred\r\n";
var splitRegexp = new RegExp(/(?:\r?\n|\r)/, 'g')
var newstr = str.replace(splitRegexp, function(match, offset, string) {
var follow = string.slice(offset);
var isLast = follow.match(splitRegexp).length == 1;
if (!isLast) {
return match + '+';
} else {
return match;
}
})
console.log(newstr)

I've replaced your regexp with visible chars so you can see what's going on:
var input = "fredEOLfredENDLfredFINfred";
input = input.replace(/(EOL|ENDL|FIN)/g, "$1+");
console.log(input);

Javascript replace utf characters in string

I want to after type Title of post automatically take value and create slug. My code works fine with English Latin characters but problem is when I type characters 'čćšđž'. Code replace first type of this characters in string but if character is repeated than is a problem. So, for testing purpose this title 'šžđčćžđš čćšđžčćšđž čćšđžčć ćčšđžšžčćšđ ćčšžčć' is converted to this slug 'szdcc'.
This is my jquery code:
$('input[name=title]').on('blur', function() {
var slugElement = $('input[name=slug]');
if(slugElement.val()) {
return;
}
slugElement.val(this.value.toLowerCase().replace('ž', 'z').replace('č','c').replace('š', 's').replace('ć', 'c').replace('đ', 'd').replace(/[^a-z0-9-]+/g, '-').replace(/^-+|-+$/g, ''));
});
How to solve this problems? Also is it possible to this few characters put in same replace() function?

Try this:
function clearText(inp) {
var wrong = 'čćšđž';
var right = 'ccsdz';
var re = new RegExp('[' + wrong + ']', 'ig');
return inp.replace(re, function (m) { return right.charAt(wrong.indexOf(m)); });
}

replace() only replaces the first occurrence unless regex is used with global modifier. You will need to change them all to regular expression.
replace(/ž/g, "z")
As far as I know, it will not be possible to use a single replace() in your case.
If you are concerned with chaining a bunch of .replace() together, you might be better off writing some custom code to replace these characters.
var newStr = "";
for (var i = 0; i < str.length; i++) {
var c = str.charAt(i);
switch (c) {
case "ž": newStr += "z"; break;
default: newStr += c; break;
}
}

How to tell if a string contains HTML entity (like &)?

I'm trying to write a function that checks a parameter against an array of special HTML entities (like the user entered '&amp' instead of '&'), and then add a span around those entered entities.
How would I search through the string parameter to find this? Would it be a regex?
This is my code thus far:
function ampersandKiller(input) {
var specialCharacters = ['&', ' ']
if($(specialCharacters).contains('&')) {
alert('hey')
} else {
alert('nay')
}
}
Obviously this doesn't work. Does anyone have any ideas?
So if a string like My name is & was passed, it would render My name is <span>&</span>. If a special character was listed twice -- like 'I really like &&& it would just render the span around each element. The user must also be able to use the plain &.

function htmlEntityChecker(input) {
var characterArray = ['&', ' '];
$.each(characterArray, function(idx, ent) {
if (input.indexOf(ent) != -1) {
var re = new RegExp(ent, "g");
input = input.replace(re, '<span>' + ent + '</span>');
}
});
return input;
}
FIDDLE

You could use this regular expression to find and wrap the entities:
input.replace(/&| /g, '<span>$&</span>')
For any kind of entity, you could use this too:
input.replace(/&(?:[a-z]+|#\d+);/g, '<span>$&</span>');
It matches the "word" entities as well as numeric entities. For example:
'test & & <'.replace(/&(?:[a-z]+|#x?\d+);/gi, '<span>$&</span>');
Output:
test & <span>&</span> <span><</span>

Another option would be to make the browser do a decode for you and check if the length is any different... check this question to see how to unescape the entities. You can then compare the length of the original string with the length of the decoded. Example below:
function htmlDecode(input){
var e = document.createElement('div');
e.innerHTML = input;
return e.childNodes.length === 0 ? "" : e.childNodes[0].nodeValue;
}
function hasEntities(input) {
if (input.length != htmlDecode(input).length) {
return true;
}
return false;
}
alert(hasEntities('a'))
alert(hasEntities('&'))
The above will show two alerts. First false and then true.

Remove all special characters except space from a string using JavaScript

I want to remove all special characters except space from a string using JavaScript.
For example,
abc's test#s
should output as
abcs tests.

You should use the string replace function, with a single regex.
Assuming by special characters, you mean anything that's not letter, here is a solution:
const str = "abc's test#s";
console.log(str.replace(/[^a-zA-Z ]/g, ""));

You can do it specifying the characters you want to remove:
string = string.replace(/[&\/\\#,+()$~%.'":*?<>{}]/g, '');
Alternatively, to change all characters except numbers and letters, try:
string = string.replace(/[^a-zA-Z0-9]/g, '');

The first solution does not work for any UTF-8 alphabet. (It will cut text such as Привіт). I have managed to create a function which does not use RegExp and use good UTF-8 support in the JavaScript engine. The idea is simple if a symbol is equal in uppercase and lowercase it is a special character. The only exception is made for whitespace.
function removeSpecials(str) {
var lower = str.toLowerCase();
var upper = str.toUpperCase();
var res = "";
for(var i=0; i<lower.length; ++i) {
if(lower[i] != upper[i] || lower[i].trim() === '')
res += str[i];
}
return res;
}
Update: Please note, that this solution works only for languages where there are small and capital letters. In languages like Chinese, this won't work.
Update 2: I came to the original solution when I was working on a fuzzy search. If you also trying to remove special characters to implement search functionality, there is a better approach. Use any transliteration library which will produce you string only from Latin characters and then the simple Regexp will do all magic of removing special characters. (This will work for Chinese also and you also will receive side benefits by making Tromsø == Tromso).

search all not (word characters || space):
str.replace(/[^\w ]/, '')

I don't know JavaScript, but isn't it possible using regex?
Something like [^\w\d\s] will match anything but digits, characters and whitespaces. It would be just a question to find the syntax in JavaScript.

I tried Seagul's very creative solution, but found it treated numbers also as special characters, which did not suit my needs. So here is my (failsafe) tweak of Seagul's solution...
//return true if char is a number
function isNumber (text) {
if(text) {
var reg = new RegExp('[0-9]+$');
return reg.test(text);
}
return false;
}
function removeSpecial (text) {
if(text) {
var lower = text.toLowerCase();
var upper = text.toUpperCase();
var result = "";
for(var i=0; i<lower.length; ++i) {
if(isNumber(text[i]) || (lower[i] != upper[i]) || (lower[i].trim() === '')) {
result += text[i];
}
}
return result;
}
return '';
}

const str = "abc's#thy#^g&test#s";
console.log(str.replace(/[^a-zA-Z ]/g, ""));

Try to use this one
var result= stringToReplace.replace(/[^\w\s]/g, '')
[^] is for negation, \w for [a-zA-Z0-9_] word characters and \s for space,
/[]/g for global

With regular expression
let string = "!#This tool removes $special *characters* /other/ than! digits, characters and spaces!!!$";
var NewString= string.replace(/[^\w\s]/gi, '');
console.log(NewString);
Result //This tool removes special characters other than digits characters and spaces
Live Example : https://helpseotools.com/text-tools/remove-special-characters

dot (.) may not be considered special. I have added an OR condition to Mozfet's & Seagull's answer:
function isNumber (text) {
reg = new RegExp('[0-9]+$');
if(text) {
return reg.test(text);
}
return false;
}
function removeSpecial (text) {
if(text) {
var lower = text.toLowerCase();
var upper = text.toUpperCase();
var result = "";
for(var i=0; i<lower.length; ++i) {
if(isNumber(text[i]) || (lower[i] != upper[i]) || (lower[i].trim() === '') || (lower[i].trim() === '.')) {
result += text[i];
}
}
return result;
}
return '';
}

Try this:
const strippedString = htmlString.replace(/(<([^>]+)>)/gi, "");
console.log(strippedString);

const input = `#if_1 $(PR_CONTRACT_END_DATE) == '23-09-2019' #
Test27919<alerts#imimobile.com> #elseif_1 $(PR_CONTRACT_START_DATE) == '20-09-2019' #
Sender539<rama.sns#gmail.com> #elseif_1 $(PR_ACCOUNT_ID) == '1234' #
AdestraSID<hello#imimobile.co> #else_1#Test27919<alerts#imimobile.com>#endif_1#`;
const replaceString = input.split('$(').join('->').split(')').join('<-');
console.log(replaceString.match(/(?<=->).*?(?=<-)/g));

Whose special characters you want to remove from a string, prepare a list of them and then user javascript replace function to remove all special characters.
var str = 'abc'de#;:sfjkewr47239847duifyh';
alert(str.replace("'","").replace("#","").replace(";","").replace(":",""));
or you can run loop for a whole string and compare single single character with the ASCII code and regenerate a new string.