This question already has answers here:
Why do regex constructors need to be double escaped?
(5 answers)
Match exact string
(3 answers)
Closed 5 years ago.
I have written the following function in javascript to validate a string that I will use as a file name. I would like to check for all the characters that are restricted by Windows OS as invalid while creating files. I checked the regular expression at RegExr, it seems to be working as expected but it doesn't work when called from an Angular controller and it only matches the first character in the parameter. I'm adding the file extension later on so that isn't a problem.
Can anybody help with it? I'm relatively new to regular expressions and would appreciate any help or pointers to useful resources.
function validateInput(value) {
if (!AngularUtils.isUndefinedOrNull(value)) {
var regex = new RegExp("[^<>/\\\\=|:*?\"]+$");
var regexOutput = regex.test(value);
if (!regex.test(value))
return true;
}
return false;
}
Edit:
Even after changing the regex to handle javascript constructors, I'm still getting valid matches for the following input: "sample_css", "sample=css","=sample"
Only the first string should be valid. jsfiddle here.
Related
This question already has answers here:
How can I validate an email address using a regular expression?
(79 answers)
Closed 2 years ago.
I have created a regular expression for email validations.
var regex = "^([a-zA-Z]+([\.-_]?[a-zA-z0-9]+)*)\#([a-zA-Z0-9]+)([-][0-9a-z]+)?\.([a-z-]{2,20})(\.[a-z]{2,3})?$"
To match emails:
1. update#update
2. mohit.bhagat#B-9com.com
3. mohit.Bhagat#us.thalesgroup.com
4. mohit#gmail.com.com.com
If you run this over online website 1 and 4th will fail while 2, 3 will pass.
But when I run this code in Javascript( Browser console ), 1st also passes the validation.
I am using Angular application.
The problem is how JS ignores \.
If you do following
var regex = "[a-z]+#[a-z]+\.[a-z]{2,3}"
Resultant string stored is
"[a-z]+#[a-z]+.[a-z]{2,3}"
And if you do this
var regex ="[a-z]+#[a-z]+[\.][a-z]{2,3}"
Resultant string stored is
"[a-z]+#[a-z]+[.][a-z]{2,3}"
Pay attention to [.] with this now i was able to get validation error for 1st email.
Complete regex: "^([a-zA-Z]+([-_.]?[a-zA-Z0-9])*)#([a-zA-Z0-9]+([-][a-z0-9A-Z]+)?)[.]([a-z]+[-_]?[a-z]+)([.][a-z]{2,3})?$"
Update:
Or you can do this: var regex ="[a-z]+#[a-z]+\\.[a-z]{2,3}"
As mentioned in comments below, you can do this way to consider . by including it in [.], but its a hack and not origional way to do it.
Best way to have . included in your regex is \.
This question already has answers here:
Why does Date.parse give incorrect results?
(11 answers)
Closed 4 years ago.
It is the first time when I met some of the bad example of data format.
All date goes for me regarding to a region of a customer.
I cannot change it. I got string:
var str = "23.01.2019 23:05:58";
in order to get
var dt = new Date(str);
I need to execute at least
str.replace(/./g,'/');
But got a weird result. (tried "split" and "join") also nothing.
Thanks a lot for any help
The . in your regular expression means any character.
Try this instead...
str.replace(/\./g,'/');
By using \. you're "escaping" the dot and saying "this has to be a dot character"
This question already has answers here:
How do you use a variable in a regular expression?
(27 answers)
Closed 6 years ago.
I'm using the <string>.replace(/x/g,"y") to replace all instances of a character in a string to a different character, and I get exactly what I need.
My problem is with the syntax of the pattern (i.e. /x/g) that causes issues in a small post-processor I developed for all the javascript files included in my project.
The solution to my problem can be to encapsulate the string replacement within an isolated file that would not undergo post-processing.
(What post-processing does and why I use it is not important here)
My question: Suppose I create a function Switch_All_Chars(In_Str,Old_C,New_C) that replaces all instances of Old_C by New_C in In_str returning the updated string, and it would loo like:
function Switch_All_Chars(In_Str,Old_C,New_C) {
pat = /Old_C/g ;
return In_Str.replace( pat , New_C) ;
}
This would not work because par is not properly defined. Is there a syntax that would allow the definition of the pattern using a variable?
Thanks.
Use RegExp constructor:
var pat = new RegExp(Old_C, "g")
This question already has answers here:
How can I delete a query string parameter in JavaScript?
(27 answers)
Closed 7 years ago.
I have a query string that I need to remove a certain parameter from. For instance, my query string may be "?name=John&page=12&mfgid=320", and I need to remove the "page" parameter from it and end up with "?name=John&mfgid=320". I cannot assume that the "page" parameter is or isn't followed by other parameters.
All my attempts at using JavaScript functions/regex are failing miserably, so I could really use a hand in getting this working. Thanks.
That's quite easy... It's just /page=\d+&?/
var uri = '?name=John&page=12&mfgid=320';
uri = uri.replace(/page=\d+&?/,'');
You can use:
uri = uri.replace(/[?&]page=[^&\n]+$|([&?])page=[^&\n]+&/g, '$1');
RegEx Demo
We'll need to use alternation to cover all the cases of presence of query parameter. Check my demo for all test cases.
This question already has answers here:
Why do regex constructors need to be double escaped?
(5 answers)
Closed 4 years ago.
I'm trying to convert following expression to "new Regexp()" style:
http://jsfiddle.net/HDWBZ/
var Wyrazenie = /\btest[a-z]*/g;
I'm really confused with it and have no idea how to fix it. Below is what I've done but obviously it doesn't work.
var Wyraznie = new RegExp("\btest[a-z]*","g");
Also have a question how would it look if instead of "test" I would use variable?
You should use this instead...
new RegExp("\\btest[a-z]*", "g");
... as \b will be interpolated into a single (slashless) character when JavaScript parser works through the corresponding string literal. The solution is to escape slash itself.
DEMO: http://jsfiddle.net/HDWBZ/1/