A JavaScript program is required to request, via a dialogue box, a password
from a user. The input, which can be of any length, must be validated such
that it is only valid if it has no spaces. Any character, other than a space, is
permissible. As soon as a space is detected, the program should terminate
with a message provided in an alert box stating:
Invalid, contains a space!
Can anyone help me correct my code, this is my attempt
<!DOCTYPE html>
<html>
<body>
<form action="">
Password: <input type="password" name="password">
</form> ;
var i ;
var validpassword = "" ;
var passworduser ;
var isNoSpace = (?!.*\\s)
if(isNoSpace = false; i > charAt(i)) //
alert("Password contains a space!")
for(j = 1; j<=yourString.length; j++){
validpassword += ’*’;
}
document.write("valid password")
else
document.write("password not valid")
</body>
</html>
var containingSpace = function(str) {
return str.indexOf(' ') > -1;
}
console.log(containingSpace('abc')); // false
console.log(containingSpace('ab c')); // true
RegEx: /\s+/
var pattern = /\s+/;
if (pattern.test(userString)) {
document.write("password not valid");
} else {
document.write("valid password");
}
Try with var isNoSpace = passworduser == passworduser.replace(" ", "");.
It will check if the passworduser string is the same even when spaces are removed. If it is, it will return true (so isNoSpace = true).
The syntax I have used is equivalent to this
var isNoSpace;
if (passworduser == passworduser.replace(" ", "")) {
isNoSpace = true;
else
isNoSpace = false;
Related
*I want to display two input fields for lower and higher number and display the necessary error messages if the inputs are wrong.
Any idea why nothing happens when I click on my button? Any way I can shorten my if-else statement cus it does feel quite wordy thank you would appreciate the comments*
<html> Enter lowest number<br>
<input type="text" id="input" size="20">
<span id="wrongInput"><br><br>
Enter highest number<br>
<input type="text" id="input2" size="20">
<span id="wrongInput2"></span><br><br>
<button type="button" onclick="testNum()">Play button</button><br><br>
</html>
<script>
function testNum()
{
//if is not a number or blank input
if (/^\d$/.test(input) == '')
{
var blank = document.getElementById("wrongInput").innerHTML;
blank.innerHTML = "Please fill in a number";
blank.style.color ="red";
return false;
} else {
blank.innerHTML = "";
}
if (/^\d$/.test(input) == false)
{
var wrong = document.getElementById("wrongInput").innerHTML;
wrong.innerHTML = "Only key in number";
wrong.style.color ="red";
return false;
} else {
wrong.innerHTML = "";
}
if (/^\d$/.test(input2) == '')
{
var blank = document.getElementById("wrongInput2").innerHTML;
blank.innerHTML = "Please fill in a number";
blank.style.color ="red";
return false;
} else {
blank.innerHTML = "";
}
if (/^\d$/.test(input2) == false)
{
var wrong = document.getElementById("wrongInput2").innerHTML;
wrong.innerHTML = "Only key in number";
wrong.style.color ="red";
return false;
} else {
wrong.innerHTML = "";
}
if (input2 < input)
{
var wrong = document.getElementById("wronginput2").innerHTML;
wrong.innerHTML = "The number must be higher";
wrong.style.color ="red";
return false;
} else {
return true;
}
}
</script>
The function is called in your example, there are just a few things listed below, that I think you should consider.
First of all you are trying to call an undefined variable in all of the else-blocks.
Second, you are calling innerHTML twice in all of the if statements.
Finally you need to take a look on your conditions in the if statements.
Okay, so I have a form. Applied a function to it.
All I want to do is when the form is submitted it launches the function, it checks to see if there is white space and throws out a message. I have the following:
function empty() {
var x;
x = document.getElementById("Username").value;
if (x == "") {
alert("Please ensure you fill in the form correctly.");
};
}
<input type='submit' value='Register' onClick='return empty()' />
<input type='text' id="Username" />
This is fine for if someone pressed the space-bar once and enters one line of whitespace, but how do I edit the function so that no matter how many spaces of whitespace are entered with the space-bar it will always throw back the alert.
Thanks in advance. I am very new to JavaScript. So please be gentle.
Trim the string before testing it.
x = document.getElementById("Username").value.trim();
This will remove any whitespace at the beginning and end of the value.
I have made a function for the same, i added another checks (including a regular expresion to detect multiples empty spaces). So here is the code:
function checkEmpty(field){
if (field == "" ||
field == null ||
field == "undefinied"){
return false;
}
else if(/^\s*$/.test(field)){
return false;
}
else{
return true;
}
}
Here is an example working with jquery: https://jsfiddle.net/p87qeL7f/
Here is the example in pure javascript: https://jsfiddle.net/g7oxmhon/
Note: the function checkEmpty still be the same for both
this work for me
$(document).ready(function() {
$('#Description').bind('input', function() {
var c = this.selectionStart,
r = /[^a-z0-9 .]/gi,
v = $(this).val();
if (r.test(v)) {
$(this).val(v.replace(r, ''));
c--;
}
this.setSelectionRange(c, c);
});
});
function checkEmpty(field) { //1Apr2022 new code
if (field == "" ||
field == null ||
field == "undefinied") {
return false;
} else if (/^\s*$/.test(field)) {
return false;
} else {
return true;
}
}
Hi i have created a javascript function to only allow numbers between 0 to 30 and character A and D. I give an alert if it does not match the criteria but if the user clicks ok on the alert the values still remain in the input and can be updated in the database. I want that user should not be able to enter anything at all in the input box except character A , D and numbers between 0 to 30 like it is done in the case of input type=number we can only enter numbers. My javascript function is:-
function validate() {
var regex = /[ad0-9]/gi;
var txt = document.getElementById('txt').value;
var valid = true;
var error = '';
if (regex.test(txt)) {
if (!isNaN(txt)) {
if (!(parseInt(txt) >= 0 && parseInt(txt) <= 30)) {
valid = false;
error = 'Please enter between 0 to 30.'
}
}
}
else {
valid = false;
error = 'Please enter between 0 to 30, A or D'
}
if (!valid) {
alert(error);
}
}
The javascript works fine with validation but after clicking ok in alert value still remains there and it also gives error when input box is empty any way to avoid that. Is there any other better way to create the function or can it done by using jquery. I am new to jquery if it is possible to do it with jquery it would be great. I would be highly gratefull if anybody can help.
You may try this code example.
function validate(box) {
var val = box.value;
if (!/^[AD]?$/.test(val) && isNaN(val) || (0 > val || 30 < val)) {
box.value = '';
alert('Only A or D or 0-30');
}
}
<input type='text' value='30' onblur='validate(this);' />
The best solution would be to check it at the moment when you are inserting it in the database.
if(txt.replace(/ /g, '').length == 0) {
// text is empty
return; // get out of function
}
If you want to make sure there is no error when the text is empty, you can do this. The .replace part is to ensure that if the text input is filled with only spaces, it is considered empty.
With the rest of the function:
function validate() {
var regex = /[ad0-9]/gi;
var txt = document.getElementById('txt').value;
var valid = true;
var error = '';
if(txt.replace(/ /g, '').length == 0) {
// text is empty
return; // get out of function
}
if (regex.test(txt)) {
if (!isNaN(txt)) {
if (!(parseInt(txt) >= 0 && parseInt(txt) <= 30)) {
valid = false;
error = 'Please enter between 0 to 30.'
}
}
}
else {
valid = false;
error = 'Please enter between 0 to 30, A or D'
}
if (!valid) {
alert(error);
}
}
How about replacing disallowed values so only the desired input is allowed. With this you won't be able to enter anything other than A, D and numbers 0 - 30:
$('input').on('input', function(e) {
this.value = this.value
.replace(/[^AD\d]/, '')
.replace(/(3)[1-9]/, '$1')
.replace(/(30)[0-9]/, '$1')
.replace(/([4-9])[0-9]/, '$1')
.replace(/([\d][\d])[\d]/, '$1');
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
<input type="text" />
Note, it's still a good idea to do some server side validation.
Hi sorry i'm still pretty new to javascript.
I've developed a form in HTML and now i'm attempting to add javascript to validate the form.
So far i have simple javascript to make sure each element is filled in,
if (document.order.suburb.value=="")
{
alert("Suburb Cannot Be Empty")
return false
}
if (document.order.postcode.value=="")
{
alert("Postcode Cannot Be Empty")
return false
}
I then have javascript to validate the length of some of the elements,
if (document.order.telephone.value.length < 10)
{
alert("Invalid Telephone Number")
return false
}
Now i'm trying to validate numeric values in the telephone number part but it's not executing correctly, it's like the code is just ignored when it's being executed.
var digits="0123456789"
var temp
var i
for (i = 0 ; i <document.order.telephone.value.length; i++)
{
temp=document.order.telephone.value.substring(i,i+1)
if (digits.indexOf(temp)==-1)
{
alert("Invalid Telephone Number")
return false
}
}
Thanks for reading and thanks for the help :) been stuck on this issue for weeks and have no idea what i'm doing wrong, i tried to code on a separate document with another form and it seemed to work fine.
EDIT
Code for validation for digits in postcode
var post = document.order.postcode.value.replace(white,'');
if(!post){
alert("Post code required !");
return false;
}
post = post.replace(/[^0-9]/g,'');//replace all other than digits
if(!post || 4 > postcode.length) {
alert("Invalid Postcode !");
return false;
}
You may try this example:
var validate = function() {
var white = /\s+/g;//for handling white spaces
var nonDigit = /[^0-9]/g; //for non digits
if(!document.order.suburb.value.replace(white, '')) {
alert("Suburb required !");
return false; //don't allow to submit
}
var post = document.order.postcode.value.replace(white, '')
if(!post) {
alert("Post code required !");
return false;
}
post = post.replace(nonDigit,'');//replace all other than digits
if(!post || 6 > post.length) { //min post code length
alert("Invalid Post code !");
return false;
}
var tel = document.order.telephone.value.replace(white, '');
if(!tel) {
alert("Telephone required !");
return false;
}
tel = tel.replace(nonDigit,'');
if(!tel || 10 > tel.length) {
alert("Invalid Telephone !");
return false;
}
return true; //return true, when above validations have passed
};
<form onsubmit="return validate();" action="#" name="order">
Suburb: <input type="text" id="suburb" name="suburb" ><br/>
Post code: <input type="text" id="postcode" name="postcode"/><br/>
Telephone: <input type="text" id="telephone" name="telephone"/><br/>
<input type="reset"/><input type="submit"/>
</form>
Here is a FIDDLE that will give you something to think about.
You could handle this task in hundreds of ways. I've just used a regex and replaced all of the non-numbers with '' - and compared the length of two variables - if there is anything other than a number the length of the regex variable will be shorter than the unchanged mytelephone.
You can do all kinds of "validation" - just me very specific in how you define "valid".
JS
var mysuburb, mypostcode, mytelephone;
$('.clickme').on('click', function(){
mysuburb = $('.suburb').val();
mypostcode = $('.postcode').val();
mytelephone = $('.telephone').val();
console.log(mysuburb + '--' + mypostcode + '--' + mytelephone);
if(mysuburb.length < 1)
{
$('.errorcode').html('');
$('.errorcode').append('Suburb is required');
return false;
}
if(mypostcode.length < 1)
{
$('.errorcode').html('');
$('.errorcode').append('postode is required');
return false;
}
if( mytelephone.length < 1 )
{
$('.errorcode').html('');
$('.errorcode').append('telephone number is required');
return false;
}
if( mytelephone.length != mytelephone.replace(/[^0-9]/g, '').length)
{
$('.errorcode').html('');
$('.errorcode').append('telephone number must contain only numbers');
return false;
}
});
I'm having a little problem with a validation thing in javascript.
<form action="insert.php" id="form" name="form" method="post"
onSubmit="return validate()">
<pre>
Vul hier de/het E-mail adres(sen) in
<textarea name="email" rows="5" cols="50"></textarea><br>
Typ hier de E-mail
<textarea name="text" rows="5" cols="50"></textarea><br>
<input type="submit" name="Submit" value="Submit">
</pre>
</form>
As you can see here, I've got two textareas. In the upper one, you're supposed to enter one or multiple email addresses underneath eachother, and in the bottom textarea you're supposed to compose the email itself. Then, when you click on submit, it'll send the email to all those specified email addresses.
Now, I've made a validation for both textareas:
function explodeArray(emailID, delimiter) {
tempArray = new Array(1);
var Count = 0;
var tempString = new String(emailID);
while (tempString.indexOf(delimiter) > 0) {
tempArray[Count] = tempString.substr(0, tempString.indexOf(delimiter));
tempString = tempString.substr(
tempString.indexOf(delimiter) + 1,
tempString.length - tempString.indexOf(delimiter) + 1
);
Count = Count + 1
}
tempArray[Count] = tempString.replace("\r", "");
return tempArray;
}
function validate() {
var emailID = document.form.email;
var delimiter = "\n";
var emailArray = explodeArray(emailID.value, delimiter);
var textID = document.form.text;
var length = emailArray.length,
element = null;
for (var i = 0; i < length; i++) {
emailVar = emailArray[i];
if (emailVar == null) {
alert("Email-adres bestaat niet")
emailID.focus()
return false
}
if (emailVar == "") {
alert("Email-adres veld is leeg")
emailID.focus()
return false
}
if (checkEmail(emailVar) == false) {
emailVar.value = ""
alert("Ongeldig E-mail adres");
emailVar.focus()
return false
}
}
if ((textID.value == null) || (textID.value == "")) {
alert("E-mail textveld is leeg")
textID.focus()
return false
}
document.getElementById("form").submit();
return true
}
function checkEmail(hallo) {
if (/^\w+([\.-]?\w+)*#\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(hallo)) {
return true
}
return false
}
(I probably copied lots of irrelevant code as well, sorry for that, just copied the whole thing just in case...)
Now what does work is:
-it won't submit when both textareas are empty;
-it won't submit when the email addresses are valid but the bottom textarea is empty;
What doesn't work is:
-the form still submits when the email addresses are invalid, even when the bottom textarea is still empty.
I've been trying to figure out for hours what could possibly be wrong here, I googled and checked stackoverflow, but I really could not find anything. Could anybody tell me what I'm doing wrong here?
Thanks in advance.
You were using emailVar.focus(); which won't execute.
Here, fixed: Live Demo
if (checkEmail(emailVar) == false) {
alert("Ongeldig E-mail adres");
emailID.focus();
return false;
}