validator.addMethod for checking before and end whitespaces - regex

I want to validate a field with white spaces either before a text string or after. It is allowed to have space in the middle string.
Here is my code
$.validator.addMethod("trimLookup", function(value, element) {
regex = "^[^\s]+(\s+[^\s]+)*$";
regex = new RegExp( regex );
return this.optional( element ) || regex.test( value );
}, $.validator.format("Cannot contains any spaces at beginning or end"));
I test the regex in https://regex101.com/ it works fine. I also test this code with other regex it works. But if enter " " or " abc " it doesn't work.
Any Suggestion?
Thank you for your time!

Related

regex to extract substring for special cases

I have a scenario where i want to extract some substring based on following condition.
search for any pattern myvalue=123& , extract myvalue=123
If the "myvalue" present at end of the line without "&", extract myvalue=123
for ex:
The string is abcdmyvalue=123&xyz => the it should return myvalue=123
The string is abcdmyvalue=123 => the it should return myvalue=123
for first scenario it is working for me with following regex - myvalue=(.?(?=[&,""]))
I am looking for how to modify this regex to include my second scenario as well. I am using https://regex101.com/ to test this.
Thanks in Advace!
Some notes about the pattern that you tried
if you want to only match, you can omit the capture group
e* matches 0+ times an e char
the part .*?(?=[&,""]) matches as least chars until it can assert eiter & , or " to the right, so the positive lookahead expects a single char to the right to be present
You could shorten the pattern to a match only, using a negated character class that matches 0+ times any character except a whitespace char or &
myvalue=[^&\s]*
Regex demo
function regex(data) {
var test = data.match(/=(.*)&/);
if (test === null) {
return data.split('=')[1]
} else {
return test[1]
}
}
console.log(regex('abcdmyvalue=123&3e')); //123
console.log(regex('abcdmyvalue=123')); //123
here is your working code if there is no & at end of string it will have null and will go else block there we can simply split the string and get the value, If & is present at the end of string then regex will simply extract the value between = and &
if you want to use existing regex then you can do it like that
var test = data1.match(/=(.*)&|=(.*)/)
const result = test[1] ? test[1] : test[2];
console.log(result);

How do I query a field from Mongo where the value is actually a number but stored as string?

The confusing part is the number in the string field can be with leading zeros but my query param will not contain that
Object 1:
{
"_id" : ObjectId("5c3f6aec29c2e3193315b485"),
"flightCode" : "000541300157840"
}
Object 2:
{
"_id" : ObjectId("5c3f6aec29c2e3193315b485"),
"flightCode" : "00054130015784"
}
If my intent is to find flight code that matches number 54130015784, how will I write my query?
You need $regex operator with following regular expression:
var code = "541300157840";
var regex = "^0*" + code + "$"
db.col.find({ flightCode: { $regex: new RegExp(regex) } })
where * means that 0 occurs zero or more times which means that it works both for 000541300157840 and for 541300157840
If you think that your data would have text flight code so the string can be identified, we can use this.
Regex:
54130015784(?="\n)
Explanation:
Positive Lookahead (?="\n)
Assert that the Regex below matches
" matches the character " literally (case sensitive)
\n matches a line-feed (newline) character (ASCII 10)
Example:
https://regex101.com/r/sF0YfH/3
Let me know if it works. If not give a clear idea what you want.

Regex Replace everything except between the first " and the last "

i need a regex that replaces everything except the content between the first " and the last ".
I need it like this:
Input String:["Key:"Value""]
And after the regex i only need this:
Output String:Key:"Value"
Thanks!
You can try something like this.
patern:
^.*?"(.*)".*$
Substion:
$1
On Regex101
Explination:
the first part ^.*?" matches as few characters as possible that are between the start of the string and a double quote
the second part(.*)" makes the largest match it can that ends in a double quote, and stuffs it all in a capture group
the last part .*$ grabs what ever is left and includes it in the match
Finally you replace the entire match with the contents of the first capture group
Can you say why you need a RegExp?
A function like:
String unquote(String input) {
int start = input.indexOf('"');
if (start < 0) return input; // or throw.
int end = input.lastIndexOf('"');
if (start == end) return input; // or throw
return input.substring(start + 1, end);
}
is going to be faster and easier to understand than a RegExp.
Anyway, for the challenge, let's say we do want a RegExp that replaces the part up to the first " and from the last " with nothing. That's two replaces, so you can do an
input.replaceAll(RegExp(r'^[^"]*"|"[^"]*$'), "")`
or you can use a capturing group and a computed replacement like:
input.replaceFirstMapped(RegExp(r'^[^"]*"([^]*)"[^"]*$'), (m) => m[1])
Alternatively, you can use the capturing group to select the text between the two and extract it in code, instead of doing string replacement:
String unquote(String input) {
var re = RegExp(r'^[^"]*"([^]*)"[^"]$');
var match = re.firstMatch(input);
if (match == null) return input; // or throw.
return match[1];
}

Getting the index of a slice

I want to do some processing on a string in Scala. The first stage of that is finding the index of articles such as: "A ", " A ", "a ", " a ". I am trying to do that like this:
"A house is in front of us".indexOfSlice("\\s+[Aa] ")
I think this should return 0, as the substring is first matched in the first position of the string.
However, this returns -1.
Why does it return -1? Is the regex I am using incorrect?
The other answers as I type this are just missing the point. Your problem is that indexOfSlice doesn't take a regexp, but a sub-sequence to seach for in the sequence. So fixing the regexp won't help at all.
Try this:
val pattern = "\\b[Aa]\\b".r.unanchored
for (mo <- pattern.findAllMatchIn("A house is in front of us, a house is in front of us all")) {
println("pattern starts at " + mo.start)
}
//> pattern starts at 0
//| pattern starts at 27
(with fixed regex, too)
Edit: counter-example for the popular but wrong suggestion of "\\s*[Aa] "
val pattern2 = "\\s*[Aa] ".r.unanchored
for (mo <- pattern2.findAllMatchIn("The agenda is hidden")) {
println("pattern starts at " + mo.start)
}
//> pattern starts at 9
I see a mistake in your regex. your regex is searching for
at least once space (\s+)
a letter (either A or a)
but string you are matching doesn't contain space in beginning. that's why It's not returning you index 0 but -1.
you could write your regex as "^\\s*[Aa] "
Here is example:
val text = "A house is in front of us";
val matcher = Pattern.compile("^\\s*[Aa] ").matcher(text)
var idx = 0;
if(matcher.find()){
idx = matcher.start()
}
println(idx)
it should return 0 as expected.

In DOORS DXL, how do I use a regular expression to determine whether a string starts with a number?

I need to determine whether a string begins with a number - I've tried the following to no avail:
if (matches("^[0-9].*)", upper(text))) str = "Title"""
I'm new to DXL and Regex - what am I doing wrong?
You need the caret character to indicate a match only at the start of a string. I added the plus character to match all the numbers, although you might not need it for your situation. If you're only looking for numbers at the start, and don't care if there is anything following, you don't need anymore.
string str1 = "123abc"
string str2 = "abc123"
string strgx = "^[0-9]+"
Regexp rgx = regexp2(strgx)
if(rgx(str1)) { print str1[match 0] "\n" } else { print "no match\n" }
if(rgx(str2)) { print str2[match 0] "\n" } else { print "no match\n" }
The code block above will print:
123
no match
#mrhobo is correct, you want something like this:
Regexp numReg = "^[0-9]"
if(numReg text) str = "Title"
You don't need upper since you are just looking for numbers. Also matches is more for finding the part of the string that matches the expression. If you just want to check that the string as a whole matches the expression then the code above would be more efficient.
Good luck!
At least from example I found this example should work:
Regexp plural = regexp "^([0-9].*)$"
if plural "15systems" then print "yes"
Resource:
http://www.scenarioplus.org.uk/papers/dxl_regexp/dxl_regexp.htm