var regex=/\u00E(0|1)/g;
I want to find à or á in the string.
Is this regex correct? Why isnt it working?
It won't work because the Unicode escape sequence \u expects four hexadecimal digits after the sequence like this: \uNNNN where each N is a hexadecimal digit.
Instead use literal characters in the regex like #Jacks soluion, or use #Fabrizio's solution.
Use instead
var regex= /[\u00E0\u00E1]/g;
You're breaking up the Unicode sequence in your expression and an unfinished sequence gets interpreted as a literal '\\u00E'.
That said, you can just put those characters in the expression itself:
var regex = /[àá]/;
regex.text('állo'); // true
Literals need to be explicit. You need
var regex=/\u00E0|\u00E1/g;
Related
I have the following set of symbols:
var a = '|\/~^:,;?!&%$#*+';
How can I check is the following string contains any of those symbols?
var b = 'avguybdf';
As suggested, regular expressions will work.
b.match(/[|\\/~^:,;?!&%$#*+]/);
EDIT: I originally used the method here https://stackoverflow.com/a/6969486/2044733 to escape the string but because of the grouping, only the backslash character needs to be escaped.
The "/" at the beginning and end of the string are the delimiters for regular expressions in javascript, and "[]" are used to group the characters. In case you're wondering how this works.
Use RegEx
Check the how to use regex # Javascript RegEx
Try one of the following examples that use regular expressions:
http://www.webdeveloper.com/forum/showthread.php?264705-Best-way-to-check-for-multiple-characters-in-a-string
http://tjvantoll.com/2013/03/14/better-ways-of-comparing-a-javascript-string-to-multiple-values/
Use RegEx. You can use test() or exec(). Read more here: http://www.w3schools.com/jsref/jsref_obj_regexp.asp
I have a custom regular expression which I use to detect whole numbers, fractions and floats.
var regEx = new RegExp("^((^[1-9]|(0\.)|(\.))([0-9]+)?((\s|\.)[0-9]+(/[0-9])?)?)$");
var quantity = 'd';
var matched = quantity.match(regEx);
alert(matched);
(The code is also found here: http://jsfiddle.net/aNb3L/ .)
The problem is that for a single letter it matches, and I can't figure out why. But for more letters it fails(which is good).
Disclaimer: I am new to regular expressions, although in http://gskinner.com/RegExr/ it doesn't match a single letter
It's easier to use straight regular expression syntax:
var regEx = /^((^[1-9]|(0\.)|(\.))([0-9]+)?((\s|\.)[0-9]+(\/[0-9])?)?)$/;
When you use the RegExp constructor, you have to double-up on the backslashes. As it is, your code only has single backslashes, so the \. subexpressions are being treated as . — and that's how single non-digit characters are slipping through.
Thus yours would also work this way:
var regEx = new RegExp("^((^[1-9]|(0\\.)|(\\.))([0-9]+)?((\\s|\\.)[0-9]+(/[0-9])?)?)$");
This happens because the string syntax also uses backslash as a quoting mechanism. When your regular expression is first parsed as a string constant, those backslashes are stripped out if you don't double them. When the string is then passed to the regular expression parser, they're gone.
The only time you really need to use the RegExp constructor is when you're building up the regular expression dynamically or when it's delivered to your code via JSON or something.
Well, for a whole number this would be your regex:
/^(0|[1-9]\d*)$/
Then you have to account for the possibility of a float:
/^(0|[1-9]\d*)(.\d+)?$/
Then you have to account for the possibility of a fraction:
/^(0|[1-9]\d*)((.\d+)|(\/[1-9]\d*)?$/
To me this regex is much easier to read than your original, but it's up to you of course.
Why isn't my code around the test function in Object RegExp working the same way as the regex pattern. Am I missing something or Am I using the wrong escape regex
<html>
<body>
<script type="text/javascript">
var str = "info#test.com";
//This isn't working
var regStr = "^([\w-]+(?:\.[\w-]+)*)#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$"; //This string can be any regex get from XSLT
//Escape function get from: http://stackoverflow.com/a/6969486/193850
regStr = regStr.replace(/[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, "\\$&");
console.log(regStr); // \^\(\[w\-\]\+\(\?:\.\[w\-\]\+\)\*\)#\(\(\?:\[w\-\]\+\.\)\*w\[w\-\]\{0,66\}\)\.\(\[a\-z\]\{2,6\}\(\?:\.\[a\-z\]\{2\}\)\?\)\$
var re = new RegExp(regStr , "i");
console.log(re.test(str)); //false
var filter=/^([\w-]+(?:\.[\w-]+)*)#((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i
console.log(filter.test(str)); //true
</script>
</body>
</html>
You have to double your backslashes when you write a regular expression as a string.
Why? The string literal syntax also observes its own backslash-quoting convention, for things like quote characters, newlines, etc. Therefore, when JavaScript parses your string constant that contains the regular expression, the backslashes will disappear. Thus, you need to quote them with another backslash so that when you pass the string to the RegExp constructor it sees the regular expression you actually intended.
See, there's a confusion. The function you've used is a nice way of preprocessing your string-to-be regexes so you don't have to worry about escaping regex metacharacters - i.e., symbols that will control the regex behaviour, and not just taken literally.
But the point is that your string has already been parsed before it was taken by this escaping function: \w and \. sequences became just w and . respectively, the preceding slash was lost.
For characters not listed in Table 2.1, a preceding backslash is
ignored, but this usage is deprecated and should be avoided.
The escaper function, actually, did restore the slash before the ., but w wasn't special for it in any kind. ) Therefore the string that went into RegExp constructor had [w] instead of [\w].
It's actually quite easy to check: just console.log(regStr) after the replacement operation.
I'd like to compare 2 strings with each other, but I got a little problem with the Brackets.
The String I want to seek looks like this:
CAPPL:LOCAL.L_hk[1].vorlauftemp_soll
Quoting those to bracket is seemingly useless.
I tried it with this code
var regex = new RegExp("CAPPL:LOCAL.L_hk\[1\].vorlauftemp_soll","gi");
var value = "CAPPL:LOCAL.L_hk[1].vorlauftemp_soll";
regex.test(value);
Somebody who can help me??
It is useless because you're using string. You need to escape the backslashes as well:
var regex = new RegExp("CAPPL:LOCAL.L_hk\\[1\\].vorlauftemp_soll","gi");
Or use a regex literal:
var regex = /CAPPL:LOCAL.L_hk\[1\].vorlauftemp_soll/gi
Unknown escape characters are ignored in JavaScript, so "\[" results in the same string as "[".
In value, you have (1) instead of [1]. So if you expect the regular expression to match and it doesn't, it because of that.
Another problem is that you're using "" in your expression. In order to write regular expression in JavaScript, use /.../g instead of "...".
You may also want to escape the dot in your expression. . means "any character that is not a line break". You, on the other hand, wants the dot to be matched literally: \..
You are generating a regular expression (in which [ is a special character that can be escaped with \) using a string (in which \ is a special character).
var regex = /CAPPL:LOCAL.L_hk\[1\].vorlauftemp_soll/gi;
hello I am trying what I thought would be a rather easy regex in Javascript but is giving me lots of trouble.
I want the ability to split a date via javascript splitting either by a '-','.','/' and ' '.
var date = "02-25-2010";
var myregexp2 = new RegExp("-.");
dateArray = date.split(myregexp2);
What is the correct regex for this any and all help would be great.
You need the put the characters you wish to split on in a character class, which tells the regular expression engine "any of these characters is a match". For your purposes, this would look like:
date.split(/[.,\/ -]/)
Although dashes have special meaning in character classes as a range specifier (ie [a-z] means the same as [abcdefghijklmnopqrstuvwxyz]), if you put it as the last thing in the class it is taken to mean a literal dash and does not need to be escaped.
To explain why your pattern didn't work, /-./ tells the regular expression engine to match a literal dash character followed by any character (dots are wildcard characters in regular expressions). With "02-25-2010", it would split each time "-2" is encountered, because the dash matches and the dot matches "2".
or just (anything but numbers):
date.split(/\D/);
you could just use
date.split(/-/);
or
date.split('-');
Say your string is:
let str = `word1
word2;word3,word4,word5;word7
word8,word9;word10`;
You want to split the string by the following delimiters:
Colon
Semicolon
New line
You could split the string like this:
let rawElements = str.split(new RegExp('[,;\n]', 'g'));
Finally, you may need to trim the elements in the array:
let elements = rawElements.map(element => element.trim());
Then split it on anything but numbers:
date.split(/[^0-9]/);
or just use for date strings 2015-05-20 or 2015.05.20
date.split(/\.|-/);
try this instead
date.split(/\W+/)