This might be pretty simple, but I am having a hard time with it. Consider the following code:
var string = 'testingT#$^%#$ESTING__--232'
string = string.match(/^\w*$/)
if (string != null)
{
string = string.join('')
string = string.toUpperCase()
}
$('#my-input').val(string)
What I want to do, is to strip all characters that aren't alphanumeric or underscore from string, and then transform that string to uppercase.
So far I did that, it works perfectly if I don't add any special characters, but when I add - or ^ to it, for example, it deletes everything from #my-input
You can do this in one step:
string = string.replace(/[^\w]/g, '').toUpperCase();
console.log(string); //=> "TESTINGTESTING__232"
var string = string.replace(/[^a-zA-Z_0-9]/g,'').toUpperCase()
Also, do you need unicode? My regex will only match a-z, and not åÉø for example.
You need use 'global' flag in regex and remove match restriction.
var str = 'testingT#$^%#$ESTING__--232';
str = str.match(/\w+/g);
if (str !== null)
{
str = str.join('');
str = str.toUpperCase();
}
$('#my-input').val(str);
Related
I want to remove all special characters except space from a string using JavaScript.
For example,
abc's test#s
should output as
abcs tests.
You should use the string replace function, with a single regex.
Assuming by special characters, you mean anything that's not letter, here is a solution:
const str = "abc's test#s";
console.log(str.replace(/[^a-zA-Z ]/g, ""));
You can do it specifying the characters you want to remove:
string = string.replace(/[&\/\\#,+()$~%.'":*?<>{}]/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.
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.
I'm wanting to extract each block of alphanumeric characters that come after underscores in a Javascript string. I currently have it working using a combination of string methods and regex like so:
var string = "ignore_firstMatch_match2_thirdMatch";
var firstValGone = string.substr(string.indexOf('_'));
// returns "_firstMatch_match2_thirdMatch"
var noUnderscore = firstValGone.match(/[^_]+/g);
// returns ["firstMatch", "match2" , "thirdMatch"]
I'm wondering if there's a way to do it purely using regex? Best I've managed is:
var string = "ignore_firstMatch_match2_thirdMatch";
var matchTry = string.match(/_[^_]+/g);
// returns ["_firstMatch", "_match2", "_thirdMatch"]
but that returns the preceding underscore too. Given you can't use lookbehinds in JS I don't know how to match the characters after, but exclude the underscore itself. Is this possible?
You can use a capture group (_([^_]+)) and use RegExp#exec in a loop while pushing the captured values into an array:
var re = /_([^_]+)/g;
var str = 'ignore_firstMatch_match2_thirdMatch';
var res = [];
while ((m = re.exec(str)) !== null) {
res.push(m[1]);
}
document.body.innerHTML = "<pre>" + JSON.stringify(res, 0, 4) + "</pre>";
Note that using a string#match() with a regex defined with a global modifier /g will lose all the captured texts, that's why you cannot just use str.match(/_([^_]+)/g).
Since lookbehind is not supported in JS the only way I can think of is using a group like this.
Regex: _([^_]+) and capture group using \1 or $1.
Regex101 Demo
var myString = "ignore_firstMatch_match2_thirdMatch";
var myRegexp = /_([^_]+)/g;
match = myRegexp.exec(myString);
while (match != null) {
document.getElementById("match").innerHTML += "<br>" + match[0];
match = myRegexp.exec(myString);
}
<div id="match">
</div>
An alternate way using lookahead would be something like this.
But it takes long in JS. Killed my page thrice. Would make a good ReDoS exploit
Regex: (?=_([A-Za-z0-9]+)) and capture groups using \1 or $1.
Regex101 Demo
Why do you assume you need regex? a simple split will do the job:
string str = "ignore_firstMatch_match2_thirdMatch";
IEnumerable<string> matches = str.Split('_').Skip(1);
I have a regular expression like this which extract the content between 2 characters and in this case its between 2 #'s
(?<=\#)(.*?)(?=\#)
and um using it as follows
var extract = str.match(/(?<=\#)(.*?)(?=\#)/).pop();
but the regex gives errors since I think I need to escape it. How do I correctly apply escape characters for the above regex?
Regex may be overkill for this task.
var result = str.split("#")[1] || "";
If there is no # in the string, result is the empty string.
If there is only one # in the string, result is everything after it.
If there are two or more # in the string, result is the substring between the first and second #.
#(.*?)#
or
#([^#]+)#
Simply use this and grab the group 1.See demo.
https://regex101.com/r/uE3cC4/14
var re = /#(.*?)#/gm;
var str = 'bazbarfoo#asad#';
var m;
while ((m = re.exec(str)) !== null) {
if (m.index === re.lastIndex) {
re.lastIndex++;
}
// View your result using the m-variable.
// eg m[0] etc.
}
My string contains some of the special characters that needs to be escaped with (\) double backslash before the string. My piece of code below:
var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";
var iChars = "!##$%^&*()+=-[]\\\';,./{}|\":<>?~_";
for (var i = 0; i < data.length; i++) {
if (iChars.indexOf(data.charAt(i)) != -1) {
console.log("Your string has special characters. \nThese are not allowed.");
return false;
}
}
Expected Result would be:
abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-
Above code finds the special characters in my string, but I wanted to add (\\) before every occurrences of the special characters. Any help on this?
Use a regex replacement:
Match:
/[!##$%^&*()+=\-[\]\\';,./{}|":<>?~_]/
Replace to:
\$&
>>> data.replace(/[!##$%^&*()+=\-[\]\\';,./{}|":<>?~_]/g, "\\$&")
... "abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-"
Regex:
([!##$%^&*()+=\[\]\\';,./{}|":<>?~_-])
Replacement string:
\$1
DEMO
> var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";
undefined
> var result = data.replace(/([!##$%^&*()+=\[\]\\';,./{}|":<>?~_-])/g, "\\$1");
undefined
> console.log(result);
abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-
Try this plug and play function.
var data = "abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-";
function escapeSpecialCaseChar(text) {
return text.replace(/[-[\]{}()*+?.,\\^$|#\s]/g, '\\$&');
}
console.log(escapeSpecialCaseChar(data));
Do you want to escape anything other than alphanumeric character then make it simple
Find what :([^a-zA-Z0-9])
Replacement: \\$1
regex101 demo
Sample code:
var re = /([^a-zA-Z0-9])/g;
var str = 'abckdef)ghijkl)-8-mno-3-(pqrstuvw-1-xyz)-5-thiaa-1-aza-';
var subst = '\\$1';
var result = str.replace(re, subst);
output: (same as expected)
abckdef\)ghijkl\)\-8\-mno\-3\-\(pqrstuvw\-1\-xyz\)\-5\-thiaa\-1\-aza\-