Here is text field.I want users to only enter value like 210,220,230,... and restrict from entering something like 215,225,...
I am looking for suggetions.I don't have much knowledge of javascript.
If you just want to prevent strings that end in '5':
document.getElementById("input").onblur = checkEND;
function checkEND() {
let firstValue = event.currentTarget.value;
if(firstValue.endsWith('5')){
warnUser()
}
}
This won't validate that the string is a valid number though.
function testInput() {
var key = window.event.keyCode;
var x = document.getElementById('textarea').value
var y = document.getElementById('textarea2').value
var z = parseInt(x, 10);
if (z+10 == y) {
document.getElementById('result').innerHTML = "valid";
} else {
document.getElementById('result').innerHTML = "invalid";
}
}
<textarea maxlength="3" id="textarea">5</textarea>
<textarea maxlength="3" id="textarea2">15</textarea>
<button onclick="testInput()">Test Input</button>
<div id="result"></div>
The first input is your first number, the second is your second number.
See Comments If Your Wondering Why This Doesn't Answer His OG Question
You can experiment with the setCustomValidity() of input elements (https://developer.mozilla.org/en-US/docs/Web/API/HTMLInputElement) from an onblur, onchange or oninput handler. If you are not satisfied with the value, set an error message, and an empty string otherwise. As long as the error message is set to non-empty, it is displayed and the form refuses to submit:
function check5() {
cgiftcardq.setCustomValidity(cgiftcardq.value.endsWith('5')?"Nope, it can not end with 5":"");
}
<form>
<input name="cgiftcardq" class="text_field" id="cgiftcardq" size="3" autocomplete="off" type="text" onblur="check5()">
<input type="submit" value="Send">
</form>
(StackOverflow snippets interfere with form submission - probably as part of security -, so successful submission just makes the form disappear)
As setCustomValidity() does not work everywhere (according to the compatibility table, it will not work on non-Andorid mobiles), classic "budget" solution may be mentioned too: you can simply disable the send button as long as you are not satisfied with the input:
function check5() {
if(cgiftcardq.value.endsWith('5')){
send.disabled=true;
message.innerHTML="Nope, it can not end with 5";
} else {
send.disabled=false;
message.innerHTML="OK";
}
}
<form>
<input name="cgiftcardq" class="text_field" id="cgiftcardq" size="3" autocomplete="off" type="text" oninput="check5()">
<input id="send" type="submit" value="Send" disabled>
</form>
<div id="message"></div>
Related
I found this example on w3schools website -
<!DOCTYPE html>
<html>
<body>
<h2>JavaScript Can Validate Input</h2>
<p>Please input a number between 1 and 10:</p>
<input id="numb">
<button type="button" onclick="myFunction()">Submit</button>
<p id="demo"></p>
<script>
function myFunction() {
var x, text;
// Get the value of the input field with id="numb"
x = document.getElementById("numb").value;
// If x is Not a Number or less than one or greater than 10
if (isNaN(x) || x < 1 || x > 10) {
text = "Input not valid";
} else {
text = "Input OK";
}
document.getElementById("demo").innerHTML = text;
}
</script>
</body>
</html>
when I input 9 - it says 'Input OK'
when I input 11 -it says 'Input not valid'
but I have following questions -
how can I force users to type the correct type I want, but if they don't, then don't allow them to submit or re-input.
you are compareing string with number!
you should parse x to an integer like:
x = parseInt(document.getElementById("numb").value);
like this <input type="number" id="numb"/>
There are several ways to listen to changes on the input for instance. One way, just changing the code in the example above is to switch to listen to changes on the number field as trigger to validate:
<input id="numb" onChange="myFunction()">
<button type="button" >Submit</button>
Then you can add more logic into the myFunction() to make sure the button can't be pressed until numbers are valid and so on, see a working example that stops the user from pressing the button until input is valid:
https://jsfiddle.net/5fg4payk/2/
Assuming you're wanting range restriction you can achieve this with the HTML5 constraint validation API in combination with type="number", min="1" and max="10".
<input type="number" min="1" max="10" step="1" id="numb" oninput="(validity.valid)||(value='');">
To prevent re-input, you need to disable the field.
document.getElementById("numb").disabled = true;
So your code becomes :
if (isNaN(x) || x < 1 || x > 10) {
text = "Input not valid";
document.getElementById("numb").disabled = true;
} else {
text = "Input OK";
}
I am a beginner in Javascript and am looking to find a solution to why the code below is not working.
I've reviewed several tutorials here on StackOverflow and believe it should work... but it's not.
The HTML looks like this:
<form id="personalInfo">
<h2>Email: </h2>
<input type="text" name="Email" id="Email">
<br>
</form>
<input type="button" onclick = "validateEmail()">
The Javascript looks like this:
function validateEmail()
{
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
var address = document.forms[personalInfo].elements[Email].value;
if (reg.test(address) == false) {
alert ("Email not valid");
return false;
}
return true;
}
By my accounts, this should pop up an alert if the email address entered by the user is not valid.
Instead, nothing happens at all. I'm not sure if the test is even run.
function validateEmail() {
// There are, I feel, better version of this regex online
// You can check "https://emailregex.com/"
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
// document.getElementById() - Easier to read & understand, and more widely used
var address = document.getElementById('Email').value;
// Corrected your returns - not the main issue in the function, but the old
// returns might have caused confusion
if (reg.test(address) == false) {
alert("Email not valid");
return false
}
return true
}
<form id="personalInfo">
<h2>Email: </h2>
<input type="text" name="Email" id="Email">
</form>
<!-- You had a typo on the onclick but has since been fixed -->
<input type="button" onclick="validateEmail()" value="Submit">
Two issues here:
1- In your HTML, you are missing an = sign here: onclick"validateEmail()" (Edit: seems you fixed it now)
2- in your Javascript, the indices personalInfo and Email are strings, wrap them in quotation marks:
var address = document.forms['personalInfo'].elements['Email'].value;
function validateEmail()
{
var reg = /^([A-Za-z0-9_\-\.]){1,}\#([A-Za-z0-9_\-\.]){1,}\.([A-Za-z]{2,4})$/;
var address = document.forms['personalInfo'].elements['Email'].value;
if (reg.test(address)== false)
{
alert ("Email not valid");
return false
}
return true;
}
<form id="personalInfo">
<h2>Email: </h2> <input type="text" name="Email" id="Email"> <br>
</form>
<input type="button" onclick="validateEmail()">
When dealing with email inputs, set the input type to email instead of text - like so:
<input name="my-email" type="email" />"
Then the browser will perform validation on the input; such as if the input doesn't have the # present.
Hello guys I'm confused with javascript code, I want a program that gets the input from the user, and if that input matches a specific value like 1234 I want it to hide part of the form. E.g.
var x=document.getElementById('pin').value;
function hidden() {
if (x.value=1234){
document.getElementById('pin').style.display="none";
}
}
<input type="number" name="pin" placeholder="Please Enter Your Pin" id="pin">
<button onclick="hidden()">Enter</button>
var x=document.getElementById('pin');
function checkPin() {
if (x.value == "1234"){
x.style.display="none";
}
}
<input type="number" name="pin" placeholder="Please Enter Your Pin" id="pin" />
<button onclick="checkPin()">Enter</button>
The value is not a native number, but a string, and you're assigning in the conditional check. Instead of '=' use '==' or '==='.
Try this:
function hidden() {
var x = document.getElementById('pin').value;
if (x === '1234'){
document.getElementById('pin').style.display = 'none';
}
}
I am making a form for a website with javascript, and I am trying to control the password field. I am using this jscript function
function passcheck() {
var pass=document.getElementById('password');
if (pass.value.length<=6)
{alert("The password must me greater the");
}
}
and the form":
<input type="password" name="password1" onchange="passcheck()">
but it doesnt function.
what can I do? please help me
I solve it. NOw my function lokk like this
function passcheck() {
var pass=document.getElementById('password1');
if (pass.value.length<=6)
{alert("The password must me greater the");
}
}
But I would like to show the message not in a alert but I would like to show it at the right af the input..How can I do thi
Now I want to dissable the button when the password is less then 6 characters. I have done this function
function passcheck() {
var pass=document.getElementById('password1');
var sb=document.getElementById('submit');
if (pass.value.length<=6)
{document.getElementById('error').style.display = 'block';
sb.disable=true;}
else
{
sb.disable=false;
}
and the html part is this
<input type="password" name="password1" id="password1" class="textinput" onchange="passcheck()"><br>
<input type="button" value="Submit" id="submit" onclick="location.href='userlogin.html'" class="button" ><br>
but the button is still enablet... What can I do?
}
You dont have an ID on that element, a better way would be to pass in this in your inline handler, and add a param to your function:
<input type="password" name="password1" onchange="passcheck(this)">
function passcheck(elem) {
var pass = elem.value;
if (pass.value.length<=6)
{
alert("The password must me greater the");
}
}
Yoy should use, OnBlur, since it activates when the cursor leaves the textbox
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/