Develop Reference

Regular expression not capturing multiple characters [duplicate]

I have a string in JavaScript (e.g., #box2), and I just want the 2 from it.
I tried:
var thestring = $(this).attr('href');
var thenum = thestring.replace(/(^.+)(\w\d+\w)(.+$)/i, '$2');
alert(thenum);
It still returns #box2 in the alert. How can I get it to work?
It needs to accommodate for any length number attached on the end.

For this specific example,
var thenum = thestring.replace(/^\D+/g, ''); // Replace all leading non-digits with nothing
In the general case:
thenum = "foo3bar5".match(/\d+/)[0] // "3"
Here's a bonus: regex generator.
function getre(str, num) {
if(str === num)
return 'nice try';
var res = [/^\D+/g,/\D+$/g,/^\D+|\D+$/g,/\D+/g,/\D.*/g, /.*\D/g,/^\D+|\D.*$/g,/.*\D(?=\d)|\D+$/g];
for(var i = 0; i < res.length; i++)
if(str.replace(res[i], '') === num)
return 'num = str.replace(/' + res[i].source + '/g, "")';
return 'no idea';
};
function update() {
$ = function(x) { return document.getElementById(x) };
var re = getre($('str').value, $('num').value);
$('re').innerHTML = 'Numex speaks: <code>' + re + '</code>';
}
<p>Hi, I'm Numex, the Number Extractor Oracle.
<p>What is your string? <input id="str" value="42abc"></p>
<p>What number do you want to extract? <input id="num" value="42"></p>
<p><button onclick="update()">Insert Coin</button></p>
<p id="re"></p>

You should try the following:
var txt = "#div-name-1234-characteristic:561613213213";
var numb = txt.match(/\d/g);
numb = numb.join("");
alert (numb);​
Result
1234561613213213

I think this regular expression will serve your purpose:
var num = txt.replace(/[^0-9]/g, '');
Where txt is your string.
It basically rips off anything that is not a digit.
I think you can achieve the same thing by using this as well:
var num = txt.replace(/\D/g, '');

Try the following: string.replace(/[^0-9]/g, ''); This will delete all non-digit characters, leaving only digits in the string
function retnum(str) {
var num = str.replace(/[^0-9]/g, '');
return parseInt(num,10);
}
console.log('abca12bc45qw'.replace(/[^0-9]/g, ''));
console.log('#box2'.replace(/[^0-9]/g, ''));

Using the match function.
var thenum = "0a1bbb2".match(/\d+$/)[0];
console.log(thenum);

And this is a snippet which extracts prices with currency and formatting:
var price = "£1,739.12";
parseFloat(price.replace(/[^\d\.]*/g, '')); // 1739.12

I tried all the combinations cited in the previous answer with this code and got it working. It was the only one that worked on that string → (12) 3456-7890
var str = "(12) 3456-7890";
str.replace(/\D+/g, '');
Result: "1234567890"
Obs: I know that a string like that will not be on the attribute, but whatever, the solution is better, because it’s more complete.

You may use the great parseInt() method.
It will convert the leading digits to a number:
parseInt("-10px");
// Will give you -10

You can extract numbers from a string using a regex expression:
let string = "xxfdx25y93.34xxd73";
let res = string.replace(/\D/g, "");
console.log(res);
Output: 25933473
Wrap it into a vanilla JavaScript function:
function onlyNumbers(text){
return text.replace(/\D/g, "");
}

For a string such as #box2, this should work:
var thenum = thestring.replace(/^.*?(\d+).*/,'$1');
jsFiddle:
http://jsfiddle.net/dmeku/

function justNumbers(string)
{
var numsStr = string.replace(/[^0-9]/g, '');
return parseInt(numsStr);
}
console.log(justNumbers('abcdefg12hijklmnop'));
You can do a function like this
function justNumbers(string)
{
var numsStr = string.replace(/[^0-9]/g, '');
return parseInt(numsStr);
}
Remember: if the number has a zero in front of it, the int won’t have it

If you want to parse a number from a price like $6,694.20, it can be done this way:
parseFloat('$6,694.20'.replace(/^\D|,+/g, ''))
Or via a function:
function parsePrice(value) {
return parseFloat(value.replace(/^\D|,+/g, ''))
}
parsePrice('$6,694.20') // 6694.2

To return an int from the string, you can do the following code. It removes all not number characters and returns an integer.
Number("strin[g]3".replace(/\D+/g, ""))

You can use a regular expression.
var txt="some text 2";
var numb = txt.match(/\d/g);
alert (numb);
That will alert 2.

let str = "Total Work Duration: 189.56 Hrs.Present: 23.5 Absent: 2";
/* The provided regex globally matches the character
"." and a digit from the string */
let numArr = str.match(/[\d\.]+/g)
/* It returns an array [189.56, ., 23.5, 2], and
uses the filter function to remove the '.' */
numArr = numArr.filter(n => n != '.')
console.log(numArr)

If someone need to preserve dots in extracted numbers:
var some = '65,87 EUR';
var number = some.replace(",",".").replace(/[^0-9&.]/g,'');
console.log(number); // returns 65.87

You can use Underscore.js' string library as follows:
var common = "#box"
var href = "#box1"
_(href).strRight(common)
The result will be: 1
See: Underscore.string
Demo:
http://jsfiddle.net/abdennour/Vyqtt/
HTML code:
<p>
<a href="#box1" >img1</a>
<a href="#box2" >img2</a>
<a href="#box3" >img3</a>
<a href="#box4" >img4</a>
</p>
<div style="font-size:30px"></div>
JavaScript code:
var comm = "#box"
$('a').click(function() {
$('div').html(_($(this).attr('href')).strRight(comm))})
If you have a suffix as follows:
href="box1az"
You can use the following demo:
http://jsfiddle.net/abdennour/Vyqtt/1/
function retrieveNumber(all, prefix, suffix) {
var left = _(all).strRight(prefix);
return _(left).strLeft(suffix);
}

Here's a solution that checks for no data:
var someStr = 'abc'; // Add 123 to string to see the inverse
var thenum = someStr.match(/\d+/);
if (thenum != null)
{
console.log(thenum[0]);
}
else
{
console.log('Not a number');
}

var elValue = "-12,erer3 4,-990.234sdsd";
var isNegetive = false;
if(elValue.indexOf("-") == 0)
isNegetive = true;
elValue = elValue.replace( /[^\d\.]*/g, '');
elValue = isNaN(Number(elValue)) ? 0 : Number(elValue);
if(isNegetive)
elValue = 0 - elValue;
alert(elValue); // -1234990.234

With regular expressions, how to get numbers from a string, for example:
String myString = "my 2 first gifts were made by my 4 brothers";
myString = myString.replaceAll("\\D+", "");
System.out.println("myString: " + myString);
The result of myString is "24".
You can see an example of this running code at http://ideone.com/iOCf5G.

Use this one-line code to get the first number in a string without getting errors:
var myInt = parseInt(myString.replace(/^[^0-9]+/, ''), 10);

Please check the below JavaScript code. There you can get only a number.
var txt = "abc1234char5678#!9";
var str = txt.match(/\d+/g, "") + '';
var s = str.split(',').join('');
alert(Number(s));
Output: 1234567789

You need to add "(/\d+/g)" which will remove all non-number text, but it will still be a string at this point. If you create a variable and "parseInt" through the match, you can set the new variables to the array values. Here is an example of how I got it to work:
var color = $( this ).css( "background-color" );
var r = parseInt(color.match(/\d+/g)[0]);
var g = parseInt(color.match(/\d+/g)[1]);
var b = parseInt(color.match(/\d+/g)[2]);

This answer will cover most of the scenarios. I came across this situation when a user tried to copy paste the phone number.
$('#help_number').keyup(function() {
$(this).val().match(/\d+/g).join("")
});
Explanation:
str = "34%^gd 5-67 6-6ds"
str.match(/\d+/g)
It will give an array of strings as output:
["34", "56766"]
 
str.match(/\d+/g).join("")
join() will convert and concatenate that array data into a single string.
Output:
"3456766"
In my example, I needed the output as 209-356-6788, so I used replace():
$('#help_number').keyup(function() {
$(this).val($(this).val().match(/\d+/g).join("").replace(/(\d{3})\-?(\d{3})\-?(\d{4})/, '$1-$2-$3'))
});

Written without a regular expression:
// Without Regex
function extractNumber(string) {
let numArray = string.split('').map(item => {
if (typeof +item === 'number' && !isNaN(+item))
return +item
})
return +numArray.join('')
}
extractNumber('#1200milion$') // 1200

In one of my projects I had to take a rating value from a string. This is what I used:
let text = '#xbox2'
let num = text.trim().
split('').
map(num => Number(num)).
filter(x => Number.isInteger(x))

Use:
changeStrangeDate(dateString: string) {
var sum = 0;
var numbers = dateString.match(/\d+/g);
if (numbers.length > 1) {
numbers.forEach(element => {
sum += parseInt(element);
}
);
}
console.log(new Date(sum).toDateString());
return new Date(sum).toUTCString();
}
You can do it like that and then call a function where you need it, with a parameter.
this.changeStrangeDate('/Date(1551401820000-0100)/');

How to get an array of multiple substrings divided by the same string/symbol/tag in Javascript

I have a string that is composed of different elements and I need to separate them at another tag in the string.
I used .split() and .pop() which worked great if there is only one element.
function getText(fullText, type) {
var partial = fullText.split('*' + type + '*').pop().split('*/' + type + '*')[0] || 'unknown';
return partial;
}
var str = "*a*Substring A*/a**b*Substring B*/b**c*Substring C*/c*"
getText(str, a) // returns 'Substring A'
However, I have now encountered multiple elements and in this case it only returns the last element.
var str = "*a*Substring A*/a**b*Substring B1*/b**b*Substring B2*/b*"
getText(str, b) // returns 'Substring B2'
How do I get an array with all the substrings between those tags?

function getText(fullText, type) {
let re = `\\*${type}\\*(.*?)\\*/${type}\\*`;
return fullText
.match(new RegExp(re, 'g'))
.map(str => str.match(new RegExp(re))[1]);
}
var str = "*a*Substring A*/a* woah *a*Substring A 2*/a*"
x = getText(str, 'a')
console.log(x)

You can use shift() to remove first element and then use map()
function getText(fullText, type) {
var partial = fullText.split('*' + type + '*')
partial.shift();
for(let i = 0;i<partial.length;i++){
partial[i] = partial[i].split('*/' + type + '*')[0]
}
return partial
}
var str = "*a*Substring A*/a**b*Substring B1*/b**b*Substring B2*/b*"
console.log(getText(str, 'b'))

The reason why you're getting the last element is because you're using pop() which just returns the last element in array:
The pop() method removes the last element from an array and returns that element. This method changes the length of the array.
You can read more about it on here website

Using pop() returns the last element in an array(the array that is created when you do your first split)
try:
function getText(fullText, type) {
var partial = fullText.split('*' + type + '*');
var result = [];
$.each(partial, function(i, item) {
var split = item.split('*/' + type + '*');
if (split.length > 1) {
result.push(split[0]);
}
});
return result;
}
var str = "*a*Substring A*/a**b*Substring B1*/b**b*Substring B2*/b*";
console.log(getText(str, 'b'));

Here's one way to do it.
function getText(fullText, type) {
var typeStr = "\*" + type + "\*";
return fullText
.split('/')
.filter(item=>item.match(typeStr.replace(/\*/g, '\\*')))
.map(item=>item
.substr(item.indexOf(typeStr) + typeStr.length)
.replace(/\*$/, ''));
}
var str = "*a*Substring A*/a**b*Substring B*/b**c*Substring C*/c*"
console.log(getText(str, 'a')); // returns 'Substring A'
var str = "*a*Substring A*/a**b*Substring B1*/b**b*Substring B2*/b*"
console.log(getText(str, 'b')); // returns 'Substring B2'
Explaining:
// this creates a str with the type to be searched
var typeStr = "\*" + type + "\*";
return fullText
// this splits all elements in your string
.split('/')
// this leaves only elements that match type...
.filter(item=>item.match(
// using a regex created with the typeStr created above
// replace escape the * char to make regex work
typeStr.replace(/\*/g, '\\*')))
// now with the remaining parts, alter them as follows...
.map(item=>item
// remove everything before type and type itself
.substr(item.indexOf(typeStr) + typeStr.length)
// remove last * char
.replace(/\*$/, ''));
EDIT
Reading #junvar's answer I noticed a pattern that I haven't noticed when I answered. That if you substitute * by < or > you have a XML pattern. So it seems to me that the OP has replaced < and > by * in order to mask this is XML parsing. If it is a XML parse, please read the most famous answer in SO:
https://stackoverflow.com/a/1732454/2752520
JUST DON'T PARSE XML WITH REGEX.

Please explain to me prototypes in javascript using the code below

I am trying to use the prototype method of writing functions that can be implemented by strings to capitalise every first letter of every word. I would like to call this function like,
var str = "Example of a string";
str.toJadenCase();
This is the function I am trying to write:
String.prototype.toJadenCase = function () {
//split the statement into each word
if (String.prototype.length !== 0)
{
var eachWord = String.prototype.split(" ");
var n = eachWord.length;
if(n !== 0)
{
//loop through the array of words
for(var i = 0; i < eachWord.length; i++){
//for each loop, split the word into individual characters
var charArray = eachWord[i].split("");
//capitalise the first element of character array
charArray[0] = charArray[0].toUpperCase();
//join all elements in character array to string
eachWord[i] = charArray.join("");
}
//join all the words to form the statement
String.prototype = eachWord.join(" ");
return String.prototype;
}
}
};
I had written it this way before:
var capitaliseInitial = function(sampleText){
var textString = sampleText;
//split the statement into each word
var eachWord = textString.split(" ");
//loop through the array of words
for(var i = 0; i < eachWord.length; i++){
//for each loop, split the word into individual characters
var charArray = eachWord[i].split("");
//capitalise the first element of character array
charArray[0] = charArray[0].toUpperCase();
//join all elements in character array to string
eachWord[i] = charArray.join("");
}
//join all the words to form the statement
textString = eachWord.join(" ");
return textString;
}

I would like to call this function like,
var str = "Example of a string";
str.toJadenCase();
You can't, strings are immutable. You would have to call it like this:
str = str.toJadenCase();
In your function, you're using String.prototype incorrectly. String.prototype is the object containing the various String-specific methods. It's assigned as the underlying prototype of all strings.
Where you're using String.prototype, you should be using this, and instead of trying to assign to it (this = ... is invalid), return the result.
The simple way to do what you're doing is to:
Split the string into an array of words, as you have
Loop through that array either building up a new string with the capitalized words via +=, or building a new array with the capitalized words and then doing Array#join at the end to put it back together.
Return the string you built
Something like this:
String.prototype.toJadenCase = function() {
var result = this;
//split the statement into each word
if (this.length !== 0) {
result = this.split(" ").map(function(word) {
return word.substring(0, 1).toUpperCase() + word.substring(1);
}).join(" ");
}
return result;
};
snippet.log("this is a test".toJadenCase());
snippet.log("oneword".toJadenCase());
snippet.log("blank: " + ("".toJadenCase()));
<!-- Script provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>
Note I've done away with the check if the array of words' length isn't 0: It can't be 0 if you've pre-checked the length as you have.

use RegExp and php like naming
str.ucwords()
String.prototype.ucwords = function() {
return this.replace(/\b\S/g,function(c){
return c.toUpperCase()
}
}

Here's how I did mine.
Split the string into an array of words, as you have
Loop through that array either building up a new string with the capitalized words via +=, or building a new array with the capitalized words and then doing Array#join at the end to put it back together.
Return the string you built
String.prototype.toJadenCase = function () { return this.split(" ").map(function(word){ return word.charAt(0).toUpperCase() + word.slice(1); }).join(" "); }

This look like one of the Code Wars Katas - this was my solution -
String.prototype.toJadenCase = function () {
// assign 'this' keyword to a variable and split String into an array
var result = this.split(" ");
/* loop through the array changing first character of each item to
uppercase & adding it to the remaining letters in each item */
for(i = 0; i < result.length; i++) {
result[i] = result[i].charAt(0).toUpperCase() + result[i].substring(1);
}
//finally return items joined back together in a string
return result.join(' ');
};

another way to do this would be like:
String.prototype.toJadenCase = function() {
return this
.split(" ")
.map(i => i.replace(i[0], i[0].toUpperCase()))
.join(" ");
};

Any javascript string function?

Some outside code is giving me a string value like..
null,402,2912,2909,2910,2913,2911,2914,2915,2388,2389,2390,
now i have to save this value to the data base but putting 0 in place of null in javascript. Is there any javascript string releated function to do this conversion?

You can simply use the replace function over and over again until all instances are replaced, but make sure that all your string will ever contain is the character sequence null or a number (and obviously the delimiting comma):
var str = "null,402,2912,null"
var index = str.indexOf("null");
while(index != -1) {
str = str.replace("null", "0");
index = str.indexOf("null");
}
You need to run a for loop because the function String.replace(search, rplc) will replace only the first instance of search with rplc. So we use the indexOf method to check, in each iteration, if the required term exists or not. Another alternative (and in my opinion, a better alternative would be:
var str = "null,402,2912,null"
var parts = str.split(",");
var data = []
for(var i=0; i<parts.length; i++) {
data[data.length] = parts[i]=="null"?0:parseInt(parts[i]);
}
Basically, what we are doing is that since you will anyways be converting this to an array of numbers (I presume, and sort of hope), we first split it into individual elements and then inspect each element to see if it is null and make the conversion accordingly.

This should answer your needs:
var str = 'null,402,2912,2909,2910,2913,2911,2914,2915,2388,2389,2390';
str.split(",").map(function (n) { var num = Number(n); return isNaN(num) ? 0 : num; });

The simplest solution is:
var inputString = new String("null,402,2912,2909,2910,2913,2911,2914,2915,2388,2389,2390,");
var outputString = inputString.replace("null", "0");

What I understood from your question is:
You want to replace null with 0 in a string.
You may use
string = "null,402,2912,2909,2910,2913,2911,2914,2915,2388,2389,2390,"
string.replace(/null/g,0)
Hope it helps.

Remove a letter(:) from a string

I have strings like Name:, Call:, Phone:....and so on in my table. I am learning jQuery and was able to access the text. My tutorial has used trim() to remove any whitespaces. But I want o remove ":" from the end of each string (and yes, it always lies in the end after calling trim() method). So how to achieve it.
Its my code:
<script type="text/javascript">
$(function ()
{
$(':input[type=text], textarea').each
(
function ()
{
var newText = 'Please enter your ' +
$(this).parent().prev().text().toLowerCase().trim();
$(this).attr('value', newText);
}).one('focus', function ()
{
this.value = '', this.className = ''
}).addClass('Watermark').css('width', '300px');
});
</script>
trim(":") did not help...

You can replace all : characters:
var str = '::a:sd:';
str = str.replace(/:/g,''); // str = 'asd';
Or use a handy rtrim() function:
String.prototype.rtrim = function(character) {
var re = new RegExp(character + '*$', 'g');
return this.replace(re, '');
};
var str = '::a:sd:';
str = str.rtrim(':'); // str = '::a:sd';

In this case just use the plain old JavaScript replace or substr methods.
You can also use a regular expression that looks for colon as the last character (the character preceding the regexp end-of-string anchor "$").
"hi:".replace(/:$/, "")
hi
"hi".replace(/:$/, "")
hi
"h:i".replace(/:$/, "")
h:i
This is a simplified, inline version of the rtrim function in Blender's answer.
EDIT: Here is a test fiddle for Blender's corrected rtrim function. Note that his RegExp will delete multiple occurrences of the specified character if the string ends with multiple instances of it consecutively (example bolded below).
http://jsfiddle.net/fGrPb/5/
input = '::a:sd:' output = '::a:sd'; input = 'hi:' output = 'hi'; input = 'hi:::' output = 'hi'; input = 'hi' output = 'hi'; input = 'h:i' output = 'h:i'

To chop the last character of a string use string.slice(0,-1)

You can use a regular expression to remove the colon (:).
Replace one instance:
var with_colon = 'Stuff:';
var regex = /([^:]*):/;
var without_colon = regex.exec(with_colon)[1];
alert(without_colon);
Result: Stuff
Replace all instances:
var with_colon = 'Stuff: Things:';
var without_colon = with_colon.replace(/([^:]*):/g,'$1');
alert(without_colon);
Result: Stuff Things

var myStr = "something:";
myStr = myStr.slice(0, -1);

var a="name:";
var b=a.split(":");
alert(b[0]);

one way is to use lastIndexOf
var str='Name:, Call:, Phone:';
var index=str.lastIndexOf(":");
alert(index);
var s=str.substring(0,index);
alert(s);
DEMO

This checks if the last character is a colon. If it is, the last character is removed.
if (str[str.length - 1] === ":") {
str = str.slice(0, -1);
}
If there can be multiple trailing colons, you can replace if with while, like this:
while (str[str.length - 1] === ":") {
str = str.slice(0, -1);
}
You could even make a generic trim function that accepts a string and a character and trims trailing instances of that character:
var trim = function(str, chr) {
while (str[str.length - 1] === ":") {
str = str.slice(0, -1);
}
return str;
}

function trim(str) {
str = str.replace(/^:*/,"");
return str.replace(/:*$/,"");
}

str = str.substring(0,str.lastIndexOf(":"));
Note that this removes everything from the last : to the end of the string (for example, any whitespace after the :).