replaceFirst , Why can’t special symbols be replaced? System.out.println(cal); // 1 * 1 + 1 <==== ??? Answer Special symbols which are used in the regular expressions need to be either escaped using or entire expression should be treated as a string literal with the help of Pattern.quote which basic…
Tag: regex
Regex for adding a word to a specific line if line does not contain the word
I have a YAML file with multiple lines and I know there’s one line that looks like this: Note that there is unknown number of whitespaces at the beginning of this line (because YAML). The line can be identified uniquely by the schemas: expression. The number of existing values for the schemas property i…
Regex for letters and numbers with any underscores in between
I’m trying to create a Regex String with the following rules The username is between 4 and 25 characters. It must start with a letter. It can only contain letters, numbers, and the underscore character. It cannot end with an underscore character. when it meets this criterion I want the output to be true…
Regular expression in java for matching string not enclosed in single quote
I’m parsing my scripts for wrong strings and have an array list with strings that shouldn’t occur in my lines of code. But some strings should pass when they are not exactly the string. Examples: list contains “FOO” and “BAR” textlines: result I’ve tried a view exampl…
Merging 2 regex that allow only English and Arabic characters
I have a string and I want to remove any other character such as (0..9!@#$%^&*()_., …) and keep only alphabetic characters. After looking up and doing some tests, I got 2 regexes formats: This should return “hello مرحبا ok”. But of course, this will return an empty string because we̵…
Regex for finding only single alphabets in a string and ignore consecutive double
I have searched a lot but I am unable to find a regex that could select only single alphabets and double them while those alphabets which are already double, should remain untouched. I tried But since this (\w)\1+ selects all double elements, my output becomes yahoooo. I tried to add negation to it !(\w)\1+ b…
Regex to match only 6letter alphanumeric words in a string
I am trying to match the 6 character word that has a combination of ONLY alphanumeric. Example String: I am currently trying regex [a-zA-Z0-9]{6} However, it matches below Output: But, what I need is only combination of alphanumeric. Something like below Desired Output Answer You may use this regex with 2 loo…
Regex to return all subdomains from a given domain
Given a domain string like aaaa.bbbb.cccc.dddd I am trying to iterate over all of its subdomains i.e. I thought this regex ((?:[a-zA-Z0-9]+.)*)([a-zA-Z0-9]+)$ should do the trick (please ignore the fact, that I am only matching these characters [a-zA-Z0-9]), however it only matches the full string. How can I …
How do I white list a phrase before validating it for special characters using Java Regex package
Hey I need to bypass the validation for substring whiteList in the string str but the rest of the string needs to be validated for the special characters ‘<‘, ‘>’, ‘$’, ‘#’, ‘@’. Assuming that substring is not repeated anywhere else in the main…
Regex match any of the words separated by slashes
I need to develop a validation pattern for catching any kind from: pdf/csv/xlsx select any separate word is simple: (pdf|csv|xlsx). However, I need to check that any combination with them separated by slash is fine as well. For example, correct flow: Incorrect: Answer You may use this regex: RegEx Demo