Develop Reference

How to input phone no in this 'xxx-xxx-xxxx' format in number input field

I want that whenever I type a number in the number input field in XXXXXXXXXX format it takes as XXX-XXX-XXXX using HTML, CSS and javascript.
Just like this snippet but without using the mask script.
$('.phone_us').mask('000-000-0000');
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://igorescobar.github.io/jQuery-Mask-Plugin/js/jquery.mask.min.js" type="text/javascript"></script>
<!--mask script-->
<input type="text" class="phone_us" />

There are some working answers here, but this solution is more stable.
Using the oninput event for instant replace and ...
Applying regex on the full string, to allow copy/paste, and finally ...
This code is shorter as well:
$('.phone_us').on('input', function() { //Using input event for instant effect
let text=$(this).val() //Get the value
text=text.replace(/\D/g,'') //Remove illegal characters
if(text.length>3) text=text.replace(/.{3}/,'$&-') //Add hyphen at pos.4
if(text.length>7) text=text.replace(/.{7}/,'$&-') //Add hyphen at pos.8
$(this).val(text); //Set the new text
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input class="phone_us" maxlength="12">
Or even without jQuery:
document.querySelector('.phone_us').addEventListener('input', function() { //Using input event for instant effect
let text=this.value //Get the value
text=text.replace(/\D/g,'') //Remove illegal characters
if(text.length>3) text=text.replace(/.{3}/,'$&-') //Add hyphen at pos.4
if(text.length>7) text=text.replace(/.{7}/,'$&-') //Add hyphen at pos.8
this.value=text; //Set the new text
});
<input class="phone_us" maxlength="12">

you could try like this
$(document).ready(function () {
$(".phone_us").keyup(function (e) {
var value = $(".phone_us").val();
if (e.key.match(/[0-9]/) == null) {
value = value.replace(e.key, "");
$(".phone_us").val(value);
return;
}
if (value.length == 3) {
$(".phone_us").val(value + "-")
}
if (value.length == 7) {
$(".phone_us").val(value + "-")
}
});
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://igorescobar.github.io/jQuery-Mask-Plugin/js/jquery.mask.min.js" type="text/javascript"></script>
<!--mask script-->
<form id="form1" runat="server">
<input type="text" maxlength="12" class="phone_us"/>
</form>

You can implement like this
document.getElementById('txtphone').addEventListener('blur', function (e) {
var x = e.target.value.replace(/\D/g, '').match(/(\d{3})(\d{3})(\d{4})/);
e.target.value = '(' + x[1] + ') ' + x[2] + '-' + x[3];
});txtphone
<input type="text" class="phone_us" id="txtphone" placeholder = "(000) 000-0000"/>

<input type="tel" id="phone" name="phone"
pattern="[0-9]{3}-[0-9]{3}-[0-9]{4}"
required>
Use HTML5 input type=tel to get phone number, and pattern attribute to specify any pattern.
[0-9]{3} represent the 0-9 numeric and 3 digits.
Then, add a hyphen (-), and use the numerics pattern again.
You can use own pattern and your country wise pattern like
[1-9]{4}-[1-9]{6} for the format 1234-567890.
Use the min-length and max-length in HTML5 to set limit.
Note that these patterns won't automatically add the hyphens, but will only allow correctly formatted input.
If you want get more patterns, search on web or see HTML5pattern.com

Pure javascript.
Enter 10 digits in the input field and click anywhere outside the input field.
var myTel = document.getElementById("tel");
myTel.addEventListener("blur", function() {
var str=myTel.value;
var pattern=/[0-9]{10}/;
if (pattern.test(str)) {
newstr=str.slice(0,3)+'-'+str.slice(3,6)+'-'+str.slice(6,10);
myTel.value=newstr;
}
else {
// bad
myTel.value='bad value: only 10 digits';
}
})
<form>
<input type="text" id="tel" name="tel" maxlength='10'>
</form>

How to add a validation error message next to a field using jQuery

Hi have a form with a few fields. Amongst them:
<div>
<label for="phoneNumber" class="label">Phone Number</label>
<input name="phoneNumber" type="text" id="phoneNumber" size="13" style="float:left;margin-right:10px;">
</div>
<div>
<input type="checkbox" name="activePN" id="activePN" checked >
<label for="activePN">Active</label>
</div>
The, when the form is submited, I want to validate the input and write next to each field for whichever field didn't validate. Like this:
$('#submit').click(function () {
var proceed = true;
var strippedPN = $('#phoneNumber').val().replace(/[^\d\.]/g, '').toString(); //strips non-digits from the string
if (strippedPN.length !== 10) {
$('#phoneNumber').text('<p>Phone number has to be 10 digits long.</p>')
proceed = false;
}
...
...
...
});
I was hopping that adding those <p> </p> tags would do it. But they don't...
Note: I also tried with html() instead of text() and with activePN instead of phoneNumber.

Use .after().
$('#phoneNumber').after('<p>Phone number has to be 10 digits long.</p>')
It might be wise to add a class to your p tag too, so you can remove them when the number is edited to be correct.

Try:
$('#submit').click(function(){
var proceed = true;
var strippedPN = $('#phoneNumber').val().replace(/[^\d\.]/g, ''); //strips non-digits from the string - already a String
if(strippedPN.length !== 10){
$('#phoneNumber').after('<p>Phone number has to be 10 digits long.</p>')
proceed = false;
}
}

Its best to use jqueryvalidation plugin.
But in some scenario may be you need to show validation message using custom code, then below may help.
Code
var errorSeen = false;
$('#txtname').keyup(function (e) {
var validInput = false; // TODO set your validation here
if (!validInput) {
var errorMessageVisible = $(".validationMessage").is(":visible");
if (errorSeen === false && errorMessageVisible === false) {
$('#txtname').style.borderColor = "red";
$('#txtname').after("<span class='validationMessage' style='color:red;'>
Name is required.</span>");
errorSeen = true;
}
}
else {
$('#txtname').style.borderColor = "";
var errorMessageVisible = $(".validationMessage").is(":visible");
if (errorMessageVisible)
$(".validationMessage").remove();
errorSeen = false;
}
});

How do I prevent invalid characters from being entered into a form?

For example, if I have a form and I don't want the user to enter numbers in it and I validate it with a function containing a regular expression, how do I prevent the invalid character the user entered (in this example, a digit) from showing up in the text form if it fails the regular expression test?
This is the function I tried and the select list I tried it on (in other words, this isn't the whole program). I tried returning false to the onkeypress event handler but what the user enters into the textbox still goes through.
function noNumbers(answer) { //returns false and displays an alert if the answer contains numbers
if (/[\d]+/.test(answer)) { // if there are numbers
window.alert("You can not enter numbers in this field");
return false;
}
}
<form action="get" enctype="application/x-www-form-urlencoded">
<select id="questions" name="questions">
<option value="no_numbers">What is the name of the city where you were born?</option>
<option value="no_letters">What is your phone number?</option>
<option value="no_numbers">What is the name of your favorite pet?</option>
<option value="no_letters">What is your social security number?</option>
<option value="no_numbers">What is your mother's maiden name?</option>
</select>
<p><input type="text" name="answer" onkeypress="validateAnswer();" /></p>
</form>

This validation works great for stripping invalid characters on the fly as you enter them in the relevant field. Example:
<form id="form1" name="form1" method="post">
Email:
<input type="text" name="email" id="email" onkeyup='res(this, emailaddr);' ; </form>
<script>
var phone = "()-+ 0123456789";
var numb = "0123456789";
var alpha = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ #-'.,";
var alphanumb = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ #-.'1234567890!?,:;£$%&*()";
var alphaname = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ,-.1234567890";
var emailaddr = "0123456789#._abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
function res(t, v) {
var w = "";
for (i = 0; i < t.value.length; i++) {
x = t.value.charAt(i);
if (v.indexOf(x, 0) != -1)
w += x;
}
t.value = w;
}
</script>
Then you would simply change the second value of the javascript call to the type of data you want entered in the field using the variables that are defined within the code.

This is the function you are looking for
function validateAnswer(src) {
var questions = document.getElementById("questions");
var rule = questions.options[questions.selectedIndex].value;
if(rule=="no_numbers") src.value = src.value.replace(/\d/g, '');
if(rule=="no_letters") src.value = src.value.replace(/\w/g, '');
}
just send the input field reference to the function and set it to onkeyup event instead:
<input type="text" name="answer" onkeyup="validateAnswer(this);" />
you should also hook the onchange event of the selectbox to reset the value of the input box. I suggest you also consider the HTML5 pattern attribute. See
the fiddle
patern attribute support
workaround for unsupported browsers

You get the key being pressed from the event object passed to the handler.
input type="text" name="answer" onkeypress="validateAnswer(this, event);" />
function validateAnswer(element, event) {
if (event.charCode) {
if (/\d/.test(String.fromCharCode(event.charCode))) {
window.alert("You can not enter numbers in this field");
return false;
}
}
}
Googling for "onkeypress event" finds many examples of this.

Make your life simpler by adding an extra parameter to your validateAnswer function like this:
<input type="text" id="answer" name="answer" onkeyup="validateAnswer(this);" />
Then you can define your validateAnswer like this:
function validateAnswer(elem){
elem.value = elem.value.replace(/[^\d]/g, '');
}
Here an example: http://jsbin.com/iwiduq/1/

Javascript - validation, numbers only

I'm trying to get my login form to only validate if only numbers were inputted. I can it to work if the input is only digits, but when i type any characters after a number, it will still validate etc. 12akf will work. 1am will work. How can i get past this?
Part of the Login
<form name="myForm">
<label for="firstname">Age: </label>
<input name="num" type="text" id="username" size="1">
<input type="submit" value="Login" onclick="return validateForm()">
function validateForm()
{
var z = document.forms["myForm"]["num"].value;
if(!z.match(/^\d+/))
{
alert("Please only enter numeric characters only for your Age! (Allowed input:0-9)")
}
}

Match against /^\d+$/. $ means "end of line", so any non-digit characters after the initial run of digits will cause the match to fail.
Edit:
RobG wisely suggests the more succinct /\D/.test(z). This operation tests the inverse of what you want. It returns true if the input has any non-numeric characters.
Simply omit the negating ! and use if(/\D/.test(z)).

here is how to validate the input to only accept numbers this will accept numbers like 123123123.41212313
<input type="text"
onkeypress="if ( isNaN(this.value + String.fromCharCode(event.keyCode) )) return false;"
/>
and this will not accept entering the dot (.), so it will only accept integers
<input type="text"
onkeypress="if ( isNaN( String.fromCharCode(event.keyCode) )) return false;"
/>
this way you will not permit the user to input anything but numbers

This one worked for me :
function validateForm(){
var z = document.forms["myForm"]["num"].value;
if(!/^[0-9]+$/.test(z)){
alert("Please only enter numeric characters only for your Age! (Allowed input:0-9)")
}
}

Late answer,but may be this will help someone
function isNumber(n) {
return !isNaN(parseFloat(n)) && isFinite(n);
}
Use will be like
nn=document.forms["myForm"]["num"].value;
ans=isNumber(nn);
if(ans)
{
//only numbers
}
This ans was found from here with huge vote
Validate numbers in JavaScript - IsNumeric()

function validateNumber(e) {
const pattern = /^[0-9]$/;
return pattern.test(e.key )
}
<input name="username" id="username" onkeypress="return validateNumber(event)">
This approach doesn't lock numlock numbers, arrows, home, end buttons and etc

The simplest solution.
Thanks to my partner that gave me this answer.
You can set an onkeypress event on the input textbox like this:
onkeypress="validate(event)"
and then use regular expressions like this:
function validate(evt){
evt.value = evt.value.replace(/[^0-9]/g,"");
}
It will scan and remove any letter or sign different from number in the field.

No need for the long code for number input restriction just try this code.
It also accepts valid int & float both values.
Javascript Approach
onload =function(){
var ele = document.querySelectorAll('.number-only')[0];
ele.onkeypress = function(e) {
if(isNaN(this.value+""+String.fromCharCode(e.charCode)))
return false;
}
ele.onpaste = function(e){
e.preventDefault();
}
}
<p> Input box that accepts only valid int and float values.</p>
<input class="number-only" type=text />
jQuery Approach
$(function(){
$('.number-only').keypress(function(e) {
if(isNaN(this.value+""+String.fromCharCode(e.charCode))) return false;
})
.on("cut copy paste",function(e){
e.preventDefault();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p> Input box that accepts only valid int and float values.</p>
<input class="number-only" type=text />
The above answers are for most common use case - validating input as a number.
But to allow few special cases like
negative numbers & showing the invalid keystrokes to user before
removing it, so below is the code snippet for such special use cases.
$(function(){
$('.number-only').keyup(function(e) {
if(this.value!='-')
while(isNaN(this.value))
this.value = this.value.split('').reverse().join('').replace(/[\D]/i,'')
.split('').reverse().join('');
})
.on("cut copy paste",function(e){
e.preventDefault();
});
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<p> Input box that accepts only valid int and float values.</p>
<input class="number-only" type=text />

Regular expressions are great, but why not just make sure it's a number before trying to do something with it?
function addemup() {
var n1 = document.getElementById("num1");
var n2 = document.getElementById("num2");
sum = Number(n1.value) + Number(n2.value);
if(Number(sum)) {
alert(sum);
} else {
alert("Numbers only, please!");
};
};

function ValidateNumberOnly()
{
if ((event.keyCode < 48 || event.keyCode > 57))
{
event.returnValue = false;
}
}
this function will allow only numbers in the textfield.

I think we do not accept long structure programming we will add everytime shot code see below answer.
<input type="text" oninput="this.value = this.value.replace(/[^0-9.]/g, ''); this.value = this.value.replace(/(\..*)\./g, '$1');" >

Using the form you already have:
var input = document.querySelector('form[name=myForm] #username');
input.onkeyup = function() {
var patterns = /[^0-9]/g;
var caretPos = this.selectionStart;
this.value = input.value.replace(patterns, '');
this.setSelectionRange(caretPos, caretPos);
}
This will delete all non-digits after the key is released.

var elem = document.getElementsByClassName("number-validation"); //use the CLASS in your input field.
for (i = 0; i < elem.length; i++) {
elem[i].addEventListener('keypress', function(event){
var keys = [48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 0];
var validIndex = keys.indexOf(event.charCode);
if(validIndex == -1){
event.preventDefault();
}
});
}

If you are using React, just do:
<input
value={this.state.input}
placeholder="Enter a number"
onChange={e => this.setState({ input: e.target.value.replace(/[^0-9]/g, '') })}
/>
<div id="root"></div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.4.2/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.21.1/babel.min.js"></script>
<script type="text/babel">
class Demo extends React.Component {
state = {
input: '',
}
onChange = e => {
let input = e.target.value.replace(/[^0-9]/g, '');
this.setState({ input });
}
render() {
return (
<div>
<input
value={this.state.input}
placeholder="Enter a number"
onChange={this.onChange}
/>
<br />
<h1>{this.state.input}</h1>
</div>
);
}
}
ReactDOM.render(<Demo />, document.getElementById('root'));
</script>

// I use this jquery it works perfect, just add class nosonly to any textbox that should be numbers only:
$(document).ready(function () {
$(".nosonly").keydown(function (event) {
// Allow only backspace and delete
if (event.keyCode == 46 || event.keyCode == 8) {
// let it happen, don't do anything
}
else {
// Ensure that it is a number and stop the keypress
if (event.keyCode < 48 || event.keyCode > 57) {
alert("Only Numbers Allowed"),event.preventDefault();
}
}
});
});

Avoid symbols like "." "," "+" "-". I tried it and it works fine.
$('#example').keypress(function (evt) {
if (evt != null && evt.originalEvent != null && /\D/.test(evt.originalEvent.key)) {
evt.preventDefault();
evt.stopImmediatePropagation();
return false;
}
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<input name="example" id="example">

checking space between text in javascript

I want to check the gap between two or more words, i have given as an input, in a text box. If there had any space, then i want to alert user that no space is allowing. I can check the existence of text simply using "if else" statement. But can't do the desired stuff in this way. My code is given below :
<script type="text/javascript">
function checkForm()
{
var cName=document.getElementById("cName").value;
var cEmail=document.getElementById("cEmail").value;
if(cName.length<1)
{
alert("Please enter both informations");
return false;
}
if(cEmail.length<1)
{
alert("Please enter your email");
return false;
}
else
{
return true;
}
}
Name : <input type="text" id="cName" name="cName"/>
<br/>
<br/>
Email : <input type="text" id="cEmail" name="cEmail"/>
<br/>
<br/>
<input type="submit" value="Go!"/>
</form>
Thankyou

Just use the match() method of strings. For example:
'Spaces here'.match(' ');
That returns true.
'Nospace'.match(' ');
That returns false.
So for what you want, just use something like this:
if(cName.match(' ')){
alert('Spaces found!');
return false;
}
Demo

your question not very clear , but i hope you want to count your words you can use the following code to split a text and by using the length property you count the word
var b = document.getElementById("cName").value;
var temp = new Array();
temp = b.split(' ');
var count= temp.length;
and if you want to validate your name field that should not use any space
if ( ^[A-Za-z]$.test(document.getElementById("cName").value) ) {
// your code;
}
if ( document.getElementById("cName").value.indexOf(' ') > 0 ) {
alert('space found');
}