I am using this regular expression in a java file to validate the password.
"^\w*(?=\w*\d)(?=\w*[a-z])(?=\w*[A-Z])\w*$"
It's showing the error :
Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \\ )
Can anybody tell me what mistake I am doing in this?(I don't know anything about regular expressions. I copied it from google.)
In Java string literals you need to escape the backslashes.
"^\\w*(?=\\w*\\d)(?=\\w*[a-z])(?=\\w*[A-Z])\\w*$"
You can also simplify your regular expression by removing the first \\w* as it is not needed.
Related
I am trying to bypass space and "-" in the regular expression in talend.
I want to replace all the characters with "_" other than numbers, letters, space and -. Below is the regular expression I wrote. It's giving me a syntax error.
row1.pl_name.replaceAll("[^a-zA-Z0-9,\s\-\"]","_").replace("\"", "").replaceAll("(,)*$", "").replace("__", "_")
Help will be greatly appreciated.
You need to escape more of your backslashes in the string literal:
"[^a-zA-Z0-9,\\s\\-\"]"
^ ^ Add these backslashes
Read the compiler message: \s and \- are invalid escape sequences.
Im trying to make a reference to a bin.
System.setProperty("mbrola.base", "C:\Users\Name\Desktop\FreeTTS\MBrola Project");
But Im getting this error:
Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \\ )
You want actual backslashes, which are usually part of escape sequences. You must escape the backslashes themselves, with another backslash.
System.setProperty("mbrola.base", "C:\\Users\\Name\\Desktop\\FreeTTS\\MBrola Project");
Yes, because this isn't a valid string literal:
"C:\Users\Name\Desktop\FreeTTS\MBrola Project"
You need to escape the backslashes:
"C:\\Users\\Name\\Desktop\\FreeTTS\\MBrola Project"
The string itself will only have the single backslashes though - you're just escaping it in source code.
Eclipse keeps on indicating there is an error in my code when I write a regular expression.
For example,
String regex = "/\((.+)\)/";
This causes eclipse to warn with a red flag:
Invalid escape sequence (valid ones are \b \t \n \f \r \" \'
\ )
How do I change this?
You must escape backslashes
String regex = "/\\((.+)\\)/";
if you want to put backslash within quotes you must use the escape sequence, \\, on the interior quotes to convey that it is part of the String literal and doesn't have any other special meaning
You need to escape all backslashes, so special characters appear "double escaped" - once for the String, once for the regular expression.
Hi i'm trying to split a string separated by vertical bars. for example:
String str = "a=1|b=2";
In java, we should do like this:
str.split("\\|");
If I use a single slash:
str.split("\|");
compiler gives errors:
Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \ )
Can anyone explain me why this happens? thanks!
Backslash \ is a special character. In the Java world it is used to escape a character.
The pipe | is a special character in the Regex world, which means "OR".
To use the pipe as a separator you need to escape it(so it can be recognized during the regex parsing), so you need to get this in your regex: \|.
But as backshlash is a special character in Java and that you are using a String object, you have to escape the backslash so it can be interpreted as the final expected final result: \|
To do so, you simply escape backslash with another backslash: \\|
The first backslash escapes the second backslash (java requirement) which escapes the pipe (regex requirement).
In Java strings, a backslash needs to be escaped with another backslash. So, while the "canonical" form of the regex is indeed \|, as a Java string, this must be written "\\|".
The following Reg Ex :-
^((((\(\d{3}\))|(\d{3}-))\d{3}-\d{4})|(\+?\d{2}((-| )\d{1,8}){1,5}))(( x| ext)\d{1,5}){0,1}$
when tried to be implemented shows
Invalid escape sequence (valid ones are \b \t \n \f \r \" \' \\ )
Can anyone help me sort out the issue?
I'm not going to try and parse this monstrous regex, but the error points to a problem with string escaping. You need to double all the backslashes.
Try the following:
^((((\\(\\d{3}\\))|(\\d{3}-))\\d{3}-\\d{4})|(\\+?\\d{2}((-| )\\d{1,8}){1,5}))(( x| ext)\\d{1,5}){0,1}$
In Java strings the \ backslash character starts an escape sequence for a 'special' character. Like \n for newline.
You can escape your strings with tools like this one here if you don't want to do it by hand.