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validate input value contain x numbers of numeric characters

I need to validate a input field which should contain at least x number of numeric characters.
eg: let say I need to input value has at least 5 numeric characters
12345 - valid
AB12345 - valid
123456 - valid
AB312312 - valid
asd - not valid
213 - not valid
First I tried with input.length, but I don't know it will have a leading letters or not, so length doesn't help for me
how should I do this validation with jquery or javascript ?

Let say you are looking at validating 5 numeric then you can use regular expression /(?=(?:[\d]){5}).
What this expression does is that;
(?=) means start looking ahead
(?:[\d]) means match digits but don't capture them
{5} means (?:[\d]) (match digit) do 5 times
"use strict";
let numbers = [ '12345', 'ABC12345', '123456', 'AB312312', 'asd', '213'];
numbers.forEach(number=> {
if (/(?=(?:[\d]){5})/.exec(number)) {
console.log(number + " is valid.");
};
});

Using regular expressions will do the trick
function check(str,x){
var pattern = '^[a-zA-Z0-9]*[0-9]{'+x+'}[a-zA-Z0-9]*$';
if(str.match(pattern)) return true;
return false;
}

How about something like this
x = 5;
myString = "AB12345";
if (myString.replace(/[^0-9]/g,"").length >= x) {
alert('valid');
} else {
alert('not valid');
}
see this jsfiddle.

If
inputValue.replace(/[^0-9]/g,"").length < 5
then input field is invalid.

Regex for alphanumeric with only one space or one hypen

I need a regular expression which needs to satisfy the following :-
It should accepts alphanumeric
only one space OR hyphen Or both can be there. But in any case it should be only one space or one hyphen
Max Total length should be 10 characters
For example valid data
W1A 1HQ
1234-456
IT-12345
12345
So far I have tried with below expression but it is not working properly
(^[a-zA-Z0-9][^\s\-].*[^\s\-][a-zA-Z0-9]){0,8}
Do I need to modify anything here ?
Edit
The solution posted here doesn't accept the combination of one space and one hypen within String.
Please provide an expression that will support all the requirement together in combinations.

You can use regex /^(?=.{0,10}$)[a-z0-9]+(?:[\s-][a-z0-9]+)?$/i
DEMO :
$('#input').on('input', function() {
$('#res').text(this.value.match(/^(?=.{0,10}$)[a-z0-9]+(?:[\s-][a-z0-9]+)?$/i) ? 'Valid' : 'Not Valid')
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input id="input">
<div id="res"></div>
Explanation here
^(?=.{0,10}$)[a-z0-9]+(?:[\s-][a-z0-9]+)?$
UPDATE :
only one space OR hyphen Or both can be there
/^(?=.{0,10}$)[a-z0-9]+(?:([\s-])[a-z0-9]*(?:(?!\1)[\s-])?[a-z0-9]+)?$/i
$('#input').on('input', function() {
$('#res').text(this.value.match(/^(?=.{0,10}$)[a-z0-9]+(?:([\s-])[a-z0-9]*(?:(?!\1)[\s-])?[a-z0-9]+)?$/i) ? 'Valid' : 'Not Valid')
})
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<input id="input">
<div id="res"></div>
^(?=.{0,10}$)[a-z0-9]+(?:([\s-])[a-z0-9]*(?:(?!\1)[\s-])?[a-z0-9]+)?$

This expression also validates:
only one space OR hyphen Or both can be there
and allows hyphens/spaces at the beggining or end of the string.
Regex
/^(?!(?:[^-]*-){2}|(?:[^ ]* ){2})[- a-z0-9]{0,10}$/i
regex101 demo
It matches:
^ Start of string
(?!(?:[^-]*-){2}|(?:[^ ]* ){2}) Not followed by: (negative lookahead)
(?:[^-]*-){2}) 2 hyphens, or
(?:[^ ]* ){2} 2 spaces
[- a-z0-9]{0,10} alphanumerics, hyphens or spaces, with max length of 10
$ End of string
Mode /i: case insensitive match
Code
str = "-ABC 123";
re = /^(?!(?:[^-]*-){2}|(?:[^ ]* ){2})[- a-z0-9]{0,10}$/i;
if (str.match(re)) {
document.body.innerText += "VALID";
} else {
document.body.innerText += "Invalid string";
}

// Parameter: String which has to be checked with a
// regular Expression.
function checkString(toCheck) {
if (toCheck.length <= 10) {
var reg = /^[a-zA-Z0-9]+(\s|-|\s-|-\s)?[a-zA-Z0-9]+$/;
if (reg.test(toCheck)) {
return true;
}
}
return false;
}
Complete example on codepen:
http://codepen.io/mizech/pen/EVMRJG

Try this one:
^(?=.{1,10}$)([a-zA-Z0-9]+\s{0,1}[a-zA-Z0-9]*\-{0,1}[a-zA-Z0-9]+)$
Detailed explanation is available here: https://regex101.com/r/hV3rJ2/1

Javascript Regular Expression for numbers

I am trying to make a HTML form that accepts a rating through an input field from the user. The rating is to be a number from 0-10, and I want it to allow up to two decimal places. I am trying to use regular expression, with the following
function isRatingGood()
{
var rating = document.getElementById("rating").value;
var ratingpattern = new RegExp("^[0-9](\.[0-9][0-9]?)?$");
if(ratingpattern.test(rating))
{
alert("Rating Successfully Inputted");
return true;
}
else
{
return rating === "10" || rating === "10.0" || rating === "10.00";
}
}
However, when I enter any 4 or 3 digit number into the field, it still works. It outputs the alert, so I know it is the regular expression that is failing. 5 digit numbers do not work. I used this previous answer as a basis, but it is not working properly for me.
My current understanding is that the beginning of the expression should be a digit, then optionally, a decimal place followed by 1 or 2 digits should be accepted.

You are using a string literal to created the regex. Inside a string literal, \ is the escape character. The string literal
"^[0-9](\.[0-9][0-9]?)?$"
produces the value (and regex):
^[0-9](.[0-9][0-9]?)?$
(you can verify that by entering the string literal in your browser's console)
\. is not valid escape sequence in a string literal, hence the backslash is ignored. Here is similar example:
> "foo\:bar"
"foo:bar"
So you can see above, the . is not escaped in the regex, hence it keeps its special meaning and matches any character. Either escape the backslash in the string literal to create a literal \:
> "^[0-9](\\.[0-9][0-9]?)?$"
"^[0-9](\.[0-9][0-9]?)?$"
or use a regex literal:
/^[0-9](\.[0-9][0-9]?)?$/

The regular expression you're using will parsed to
/^[0-9](.[0-9][0-9]?)?$/
Here . will match any character except newline.
To make it match the . literal, you need to add an extra \ for escaping the \.
var ratingpattern = new RegExp("^[0-9](\\.[0-9][0-9]?)?$");
Or, you can simply use
var ratingPattern = /^[0-9](\.[0-9][0-9]?)?$/;
You can also use \d instead of the class [0-9].
var ratingPattern = /^\d(\.\d{1,2})?$/;
Demo
var ratingpattern = new RegExp("^[0-9](\\.[0-9][0-9]?)?$");
function isRatingGood() {
var rating = document.getElementById("rating").value;
if (ratingpattern.test(rating)) {
alert("Rating Successfully Inputted");
return true;
} else {
return rating === "10" || rating === "10.0" || rating === "10.00";
}
}
<input type="text" id="rating" />
<button onclick="isRatingGood()">Check</button>

Below find a regex candidate for your task:
^[0-1]?\d(\.\d{0,2})?$
Demo with explanation
var list = ['03.003', '05.05', '9.01', '10', '10.05', '100', '1', '2.', '2.12'];
var regex = /^[0-1]?\d(\.\d{0,2})?$/;
for (var index in list) {
var str = list[index];
var match = regex.test(str);
console.log(str + ' : ' + match);
}

This should also do the job. You don't need to escape dots from inside the square brackets:
^((10|\d{1})|\d{1}[.]\d{1,2})$
Also if you want have max rating 10 use
10| ---- accept 10
\d{1})| ---- accept whole numbers from 0-9 replace \d with [1-9]{1} if don't want 0 in this
\d{1}[.]\d{1,2} ---- accept number with two or one numbers after the coma from 0 to 9
LIVE DEMO: https://regex101.com/r/hY5tG4/7
Any character except ^-]\ All characters except the listed special characters are literal characters that add themselves to the character class. [abc] matches a, b or c literal characters

Just answered this myself.
Need to add square brackets to the decimal point, so the regular expression looks like
var ratingpattern = new RegExp("^[0-9]([\.][0-9][0-9]?)?$");

javascript number validation function

i need a javascript function that able to check for digit and - only.
example: 1,2,3,4,5,6,7,8,9,0 will return true
and - will return true as well.
other than that all return false including enter is pressed.
i have a function like this:
function IsNumeric(sText){
var filter = /^[0-9-+]+$/;
if (filter.test(sText)) {
return true;
}else {
return false;
}
}
i call it like this:
if(!IsNumeric(value)) {
alert("Number and - only please");
}
for some reason it does not work, any method to do the verification without using regex?

EDIT: OK, updated as per your comment, an expression to match either a lone minus sign or any combination of digits with no minus sign:
function IsNumeric(sText){
return /^(-|\d+)$/.test(sText);
}
If you want only positive numbers and don't want to allow leading zeros then use this regex:
/^(-|[1-9]\d*)$/
Regarding your question "any method to do the verification without using regex?", yes, there are endless ways to achieve this with the various string and number manipulation functions provided by JS. But a regex is simplest.
Your function returns true if the supplied value contains any combination of digits and the plus or minus symbols, including repeats such as in "---+++123". Note that the + towards the end of your regex means to match the preceding character 1 or more times.
What you probably want is a regex that allows a single plus or minus symbol at the beginning, followed by any combination of digits:
function IsNumeric(sText){
return /^[-+]?\d+$/.test(sText);
}
? means match the preceding character 0 or 1 times. You can simplify [0-9] as \d. Note that you don't need the if statement: just return the result from .test() directly.
That will accept "-123", "123", "+123" but not "--123". If you don't want to allow a plus sign at the beginning change the regex to /^-?\d+$/.
"example: 1,2,3,4,5,6,7,8,9,0 will return true and - will return true as well."
Your example seems to be saying that only a single digit or a single minus sign is considered valid - if so then try this:
function IsNumeric(sText){
return /^[\d-]$/.test(sText);
}

How about
function IsNumeric(s) {
return /^(+|-|)\d*$/.test(s);
}

Hiphen(-) has special meaning so use escape character in character set.
Try this:
var filter = /^[0-9\-]+$/;

Can be simple ... try this:
function IsNumeric(str) {
return str.length == 1 && (parseInt(str) < 10 || str == "-");
}

RegEx for Javascript to allow only alphanumeric

I need to find a reg ex that only allows alphanumeric. So far, everyone I try only works if the string is alphanumeric, meaning contains both a letter and a number. I just want one what would allow either and not require both.

/^[a-z0-9]+$/i
^ Start of string
[a-z0-9] a or b or c or ... z or 0 or 1 or ... 9
+ one or more times (change to * to allow empty string)
$ end of string
/i case-insensitive
Update (supporting universal characters)
if you need to this regexp supports universal character you can find list of unicode characters here.
for example: /^([a-zA-Z0-9\u0600-\u06FF\u0660-\u0669\u06F0-\u06F9 _.-]+)$/
this will support persian.

If you wanted to return a replaced result, then this would work:
var a = 'Test123*** TEST';
var b = a.replace(/[^a-z0-9]/gi, '');
console.log(b);
This would return:
Test123TEST
Note that the gi is necessary because it means global (not just on the first match), and case-insensitive, which is why I have a-z instead of a-zA-Z. And the ^ inside the brackets means "anything not in these brackets".
WARNING: Alphanumeric is great if that's exactly what you want. But if you're using this in an international market on like a person's name or geographical area, then you need to account for unicode characters, which this won't do. For instance, if you have a name like "Âlvarö", it would make it "lvar".

Use the word character class. The following is equivalent to a ^[a-zA-Z0-9_]+$:
^\w+$
Explanation:
^ start of string
\w any word character (A-Z, a-z, 0-9, _).
$ end of string
Use /[^\w]|_/g if you don't want to match the underscore.

/^([a-zA-Z0-9 _-]+)$/
the above regex allows spaces in side a string and restrict special characters.It Only allows
a-z, A-Z, 0-9, Space, Underscore and dash.

^\s*([0-9a-zA-Z]*)\s*$
or, if you want a minimum of one character:
^\s*([0-9a-zA-Z]+)\s*$
Square brackets indicate a set of characters. ^ is start of input. $ is end of input (or newline, depending on your options). \s is whitespace.
The whitespace before and after is optional.
The parentheses are the grouping operator to allow you to extract the information you want.
EDIT: removed my erroneous use of the \w character set.

For multi-language support:
var filtered = 'Hello Привет 你好 123_456'.match(/[\p{L}\p{N}\s]/gu).join('')
console.log(filtered) // --> "Hello Привет 你好 123456"
This matches any letter, number, or space in most languages.
[...] -> Match with conditions
[ab] -> Match 'a' OR 'b'
\p{L} -> Match any letter in any language
\p{N} -> Match any number in any language
\s -> Match a space
/g -> Don't stop after first match
/u -> Support unicode pattern matching
Ref: https://javascript.info/regexp-unicode

This will work
^(?=.*[a-zA-Z])(?=.*[0-9])[a-zA-Z0-9]+$
It accept only alphanumeriuc characters alone:
test cases pased :
dGgs1s23 - valid
12fUgdf - valid,
121232 - invalid,
abchfe - invalid,
abd()* - invalid,
42232^5$ - invalid
or
You can also try this one. this expression satisfied at least one number and one character and no other special characters
^(?=.*[0-9])(?=.*[a-zA-Z])([a-zA-Z0-9]+)$
in angular can test like:
$scope.str = '12fUgdf';
var pattern = new RegExp('^(?=.*[0-9])(?=.*[a-zA-Z])([a-zA-Z0-9]+)$');
$scope.testResult = pattern.test($scope.str);
PLUNKER DEMO
Refered:Regular expression for alphanumeric in Angularjs

Instead of checking for a valid alphanumeric string, you can achieve this indirectly by checking the string for any invalid characters. Do so by checking for anything that matches the complement of the valid alphanumeric string.
/[^a-z\d]/i
Here is an example:
var alphanumeric = "someStringHere";
var myRegEx = /[^a-z\d]/i;
var isValid = !(myRegEx.test(alphanumeric));
Notice the logical not operator at isValid, since I'm testing whether the string is false, not whether it's valid.

I have string similar to Samsung Galaxy A10s 6.2-Inch (2GB,32GB ROM) Android 9.0, (13MP+2MP)+ 8MP Dual SIM 4000mAh 4G LTE Smartphone - Black (BF19)
Below is what i did:
string.replace(/[^a-zA-Z0-9 ,._-]/g, '').split(',').join('-').split(' ').join('-').toLowerCase()
Notice i allowed ,._- then use split() and join() to replace , to - and space to - respectively.
I ended up getting something like this:
samsung-galaxy-a10s-6.2-inch-2gb-32gb-rom-android-9.0-13mp-2mp-8mp-dual-sim-4000mah-4g-lte-smartphone-black-bf19-20 which is what i wanted.
There might be a better solution but this is what i found working fine for me.

Extend the string prototype to use throughout your project
String.prototype.alphaNumeric = function() {
return this.replace(/[^a-z0-9]/gi,'');
}
Usage:
"I don't know what to say?".alphaNumeric();
//Idontknowwhattosay

Even better than Gayan Dissanayake pointed out.
/^[-\w\s]+$/
Now ^[a-zA-Z0-9]+$ can be represented as ^\w+$
You may want to use \s instead of space. Note that \s takes care of whitespace and not only one space character.

Input these code to your SCRATCHPAD and see the action.
var str=String("Blah-Blah1_2,oo0.01&zz%kick").replace(/[^\w-]/ig, '');

JAVASCRIPT to accept only NUMBERS, ALPHABETS and SPECIAL CHARECTERS
document.getElementById("onlynumbers").onkeypress = function (e) {
onlyNumbers(e.key, e)
};
document.getElementById("onlyalpha").onkeypress = function (e) {
onlyAlpha(e.key, e)
};
document.getElementById("speclchar").onkeypress = function (e) {
speclChar(e.key, e)
};
function onlyNumbers(key, e) {
var letters = /^[0-9]/g; //g means global
if (!(key).match(letters)) e.preventDefault();
}
function onlyAlpha(key, e) {
var letters = /^[a-z]/gi; //i means ignorecase
if (!(key).match(letters)) e.preventDefault();
}
function speclChar(key, e) {
var letters = /^[0-9a-z]/gi;
if ((key).match(letters)) e.preventDefault();
}
<html>
<head></head>
<body>
Enter Only Numbers:
<input id="onlynumbers" type="text">
<br><br>
Enter Only Alphabets:
<input id="onlyalpha" type="text" >
<br><br>
Enter other than Alphabets and numbers like special characters:
<input id="speclchar" type="text" >
</body>
</html>

A little bit late, but this worked for me:
/[^a-z A-Z 0-9]+/g
a-z : anything from a to z.
A-Z : anything from A to Z (upper case).
0-9 : any number from 0 to 9.
It will allow anything inside square brackets, so let's say you want to allow any other character, for example, "/" and "#", the regex would be something like this:
/[^a-z A-Z 0-9 / #]+/g
This site will help you to test your regex before coding.
https://regex101.com/
Feel free to modify and add anything you want into the brackets.
Regards :)

It seems like many users have noticed this these regular expressions will almost certainly fail unless we are strictly working in English. But I think there is an easy way forward that would not be so limited.
make a copy of your string in all UPPERCASE
make a second copy in all lowercase
Any characters that match in those strings are definitely not alphabetic in nature.
let copy1 = originalString.toUpperCase();
let copy2 = originalString.toLowerCase();
for(let i=0; i<originalString.length; i++) {
let bIsAlphabetic = (copy1[i] != copy2[i]);
}
Optionally, you can also detect numerics by just looking for digits 0 to 9.

Try this... Replace you field ID with #name...
a-z(a to z),
A-Z(A to Z),
0-9(0 to 9)
jQuery(document).ready(function($){
$('#name').keypress(function (e) {
var regex = new RegExp("^[a-zA-Z0-9\s]+$");
var str = String.fromCharCode(!e.charCode ? e.which : e.charCode);
if (regex.test(str)) {
return true;
}
e.preventDefault();
return false;
});
});

Save this constant
const letters = /^[a-zA-Z0-9]+$/
now, for checking part use .match()
const string = 'Hey there...' // get string from a keyup listner
let id = ''
// iterate through each letters
for (var i = 0; i < string.length; i++) {
if (string[i].match(letters) ) {
id += string[i]
} else {
// In case you want to replace with something else
id += '-'
}
}
return id

Alphanumeric with case sensitive:
if (/^[a-zA-Z0-9]+$/.test("SoS007")) {
alert("match")
}

Also if you were looking for just Alphabetical characters, you can use the following regular expression:
/[^a-zA-Z]/gi
Sample code in typescript:
let samplestring = "!#!&34!# Alphabet !!535!!! is safe"
let regex = new RegExp(/[^a-zA-Z]/gi);
let res = samplestring.replace(regex,'');
console.log(res);
Note: if you are curious about RegEx syntax, visit regexr and either use the cheat-sheet or play with regular expressions.
Edit: alphanumeric --> alphabetical

Only accept numbers and letters (No Space)
function onlyAlphanumeric(str){
str.value=str.value.replace(/\s/g, "");//No Space
str.value=str.value.replace(/[^a-zA-Z0-9 ]/g, "");
}
<div>Only accept numbers and letters </div>
<input type="text" onKeyUp="onlyAlphanumeric(this);" >

Here is the way to check:
/**
* If the string contains only letters and numbers both then return true, otherwise false.
* #param string
* #returns boolean
*/
export const isOnlyAlphaNumeric = (string: string) => {
return /^(?=.*[a-zA-Z])(?=.*[0-9])[a-zA-Z0-9]+$/.test(string);
}

Jquery to accept only NUMBERS, ALPHABETS and SPECIAL CHARECTERS
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
</head>
<body>
Enter Only Numbers:
<input type="text" id="onlynumbers">
<br><br>
Enter Only Alphabets:
<input type="text" id="onlyalpha">
<br><br>
Enter other than Alphabets and numbers like special characters:
<input type="text" id="speclchar">
<script>
$('#onlynumbers').keypress(function(e) {
var letters=/^[0-9]/g; //g means global
if(!(e.key).match(letters)) e.preventDefault();
});
$('#onlyalpha').keypress(function(e) {
var letters=/^[a-z]/gi; //i means ignorecase
if(!(e.key).match(letters)) e.preventDefault();
});
$('#speclchar').keypress(function(e) {
var letters=/^[0-9a-z]/gi;
if((e.key).match(letters)) e.preventDefault();
});
</script>
</body>
</html>
**JQUERY to accept only NUMBERS , ALPHABETS and SPECIAL CHARACTERS **
<!DOCTYPE html>
$('#onlynumbers').keypress(function(e) {
var letters=/^[0-9]/g; //g means global
if(!(e.key).match(letters)) e.preventDefault();
});
$('#onlyalpha').keypress(function(e) {
var letters=/^[a-z]/gi; //i means ignorecase
if(!(e.key).match(letters)) e.preventDefault();
});
$('#speclchar').keypress(function(e) {
var letters=/^[0-9a-z]/gi;
if((e.key).match(letters)) e.preventDefault();
});
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.4.1/jquery.min.js">
Enter Only Numbers:
Enter Only Alphabets:
Enter other than Alphabets and numbers like special characters:
</body>
</html>