How to implement javascript validation? - javascript

I'm trying to get this code to work, but it's not working. I want to validate something with JavaScript
Code:
function validate() {
var letters = /^[A-Za-z]_$/;
u = document.getElementById("username").value;
if (validate.value.match(letters) {
return true;
} else {
alert("username is requiried");
return false;
}
}
return true;
}

Your code is not proper and also have lots of mistakes. I have corrected and implemented validations. Try the below code.
<script>
function validate() {
var u = document.getElementById("username").value;
var p = document.getElementById("password").value;
var letters = /^[A-Za-z]_$/;
if(u == '') {
alert("username is required");
return false;
}
if(!u.match(letters)) {
alert("username should be letters");
return false;
}
if(p == '') {
alert("password is required");
return false;
}
if(p.length < 6) {
alert("password length is too short");
return false;
}
return true;
}
</script>
Hope this will help

Related

How do i return two alerts in JS?

I wrote this code for validate password and i need to show user two different alerts.
(pw.length < 8) when this condition executed "Password need minimum 8 characters"
(pw != cpw) "Passwords does not match"
I already tried all if statements but it not gonna help.
<script>
function validatePassword(){
var pw= document.getElementById("txtPassword").value;
var cpw= document.getElementById("txtCPassword").value;
if((pw.length < 8)||(pw != cpw))
{
alert("please enter the correct password")
return false;
Event.preventDefault();
}
return true;
}
</script>
Does anyone know if something...
Use a boolean and two if statements. Return the boolean at the end for true or false.
function validatePassword() {
const pw = document.getElementById("txtPassword").value;
const cpw = document.getElementById("txtCPassword").value;
let isValid = true;
if (pw.length < 8) {
alert('Password is not long enough. Minimum length is 8 characters.');
isValid = false;
}
if(pw !== cpw)) {
alert('Passwords do not match'.);
isValid = false;
}
return isValid;
}
Or have both messages in one alert using an array
function validatePassword() {
const pw = document.getElementById("txtPassword").value;
const cpw = document.getElementById("txtCPassword").value;
const errors = [];
if (pw.length < 8) {
errors.push('Password is not long enough. Minimum length is 8 characters.');
}
if(pw !== cpw)) {
errors.push('Passwords do not match.');
}
if (errors.length) {
alert(errors.join('\n'));
return false;
}
return true;
}
here is most basic version you can use this type of code.
function validatePassword(){
var pw= document.getElementById("txtPassword").value;
var cpw= document.getElementById("txtCPassword").value;
if((pw.length < 8))
{
alert("please enter the correct password")
return false;
} else if((cpw != pw)) {
alert("Passwords does not match")
} else {
alert("Password is correct!")
return true;
}
}
<form id="form">
<input type="text" id="txtPassword">
<input type="text" id="txtCPassword">
<input onclick="event.preventDefault();validatePassword()" type="submit" value="Submit">
</form>
This will do.
<script>
var pw= document.getElementById("txtPassword").value;
var cpw= document.getElementById("txtCPassword").value;
function validatePassword(){
if(pw.length < 8)
{
alert("Password need minimum 8 characters")
}
if(pw != cpw){
alert("Passwords does not match")
}
}
I don't think you need to show 2 alerts. When txtPassword is invalid, users have to retype both passwords whether passwords match or not. There is no point in showing "Passwords does not match" message in that case.
To know how to show 2 alerts, see my second code.
First, here is another solution:
const FORM = document.querySelector('#form');
const PSW = document.querySelector('#txtPassword');
const C_PSW = document.querySelector('#txtCPassword');
FORM.addEventListener('submit', event => {
event.preventDefault();
if (!validatePassword()) return;
console.log('Submitted');
})
function validatePassword() {
let pw = PSW.value;
let cpw = C_PSW.value;
if (pw.length < 8) {
alert('please enter the correct password');
return;
} else if (pw !== cpw) {
alert('Passwords does not match');
return;
}
return true;
}
<form action="" id="form">
<input type="password" id="txtPassword">
<input type="password" id="txtCPassword">
<input type="submit" value="Submit">
</form>
To show 2 alerts:
function validatePassword() {
let pw = PSW.value;
let cpw = C_PSW.value;
if (pw.length < 8) {
alert('please enter the correct password');
if (pw !== cpw) {
alert('Passwords does not match');
}
return;
} else if (pw !== cpw) {
alert('Passwords does not match');
return;
}
return true;
}

is this correct regarding about the validation confirmation password and letter only text

is this correct regarding the validation confirmation password and letter-only text. It is not working pls help. THANKS!
function validation(password, confirmpassword) {
var password = document.form.password.value;
var confirmpassword = document.form.confirmpassword.value;
if (password.length <= 6) {
alert("password must be more thank 6 characters long");
return false;
}
if (password.value !== confirmpassword.value)
alert("password should match");
return false;
}
function allLetter(inputtxt) {
var letters = /^[a-z]*$/i;
if (!inputtxt.value.match(letters)) {
alert("Please input letters only");
}
}
Here's how you can do it:
function validation(event) {
event.preventDefault();
var password = document.querySelector(".password").value;
var confirmpassword = document.querySelector(".confirm-password").value;
if (password.length <= 6) {
alert("password must be more thank 6 characters long");
return false;
}
if (password !== confirmpassword) {
alert("password should match");
return false;
}
alert("password valid");
return true;
}
function allLetter(inputtxt) {
var letters = /^[a-z]*$/i;
if (!letters.test(inputtxt)) {
alert("Please input letters only");
}
}
const passwordInputs = document.querySelectorAll("input[type=password]");
const validator = document.querySelector(".validate");
passwordInputs.forEach(function(passwordInput) {
passwordInput.addEventListener("input", function(e) {
allLetter(e.target.value);
});
});
validator.addEventListener("click", function(event) {
console.log("can proceed", validation(event));
});
<form>
<input class="password" type="password"></input>
<input class="confirm-password" type="password"></input>
<button class="validate">Validate</button>
</form>

JavaScript: How can I make this console.log() work?

The third log doesn't go through, does anyone know why??
I've been trying to figure out for a while, and I've been struggling a lot.
var KnowsUsername = true;
var KnowsEmail = true;
var KnowsPassword = true;
setTimeout(function(){
var Username = prompt('What is your username?');
if(Username == '') {
KnowsUsername = true;
console.log("Correct username!");
} else {
KnowsUsername = false;
console.error('\x1b[31m%s\x1b[0m', 'Aww! wrong username! try again!');
}
if (KnowsUsername == false) {
return;
} else {
if (KnowsUsername == true) {
var Email = prompt('What is your E-mail?');
if(Email == '') {
KnowsEmail = true;
console.log("Correct E-mail!");
} else {
KnowsEmail = false;
console.error('\x1b[31m%s\x1b[0m', 'Wrong E-mail! try again!');
}
}
if (KnowsEmail == false) {
return;
} else {
if (KnowsEmail == true) {
var Password = prompt('What is your password?');
if (!Password == '') {
KnowsPassword = false;
console.error('\x1b[31m%s\x1b[0m', 'Aww! wrong password! try again!');
}
} else {
if(Password == '') {
KnowsPassword = true;
}
console.log("Correct password!");
}
}
}
}, 2100);
The last console.log doesn't work. I've tried changing it a bunch of times, and none of them worked.
Your if-else statement for KnowsEmail == true is incorrect.
I've fixed incorrect statements and also removed unnecessary satements.
var KnowsUsername = true;
var KnowsEmail = true;
var KnowsPassword = true;
setTimeout(function () {
var Username = prompt('What is your username?');
if (Username == '') {
KnowsUsername = true;
console.log('Correct username!');
var Email = prompt('What is your E-mail?');
if (Email == '') {
KnowsEmail = true;
console.log('Correct E-mail!');
var Password = prompt('What is your password?');
if (Password == '') {
KnowsPassword = true;
console.log('Correct password!');
} else {
KnowsPassword = false;
console.error('\x1b[31m%s\x1b[0m', 'Aww! wrong password! try again!');
}
} else {
KnowsEmail = false;
console.error('\x1b[31m%s\x1b[0m', 'Wrong E-mail! try again!');
}
} else {
KnowsUsername = false;
console.error('\x1b[31m%s\x1b[0m', 'Aww! wrong username! try again!');
}
}, 2100);

How do I correctly perform form validation in JavaScript?

I am having a hard time trying to do a correct form validation. I have Name, Email, and Phone Number fields. I implemented the validation check for all of them and when I click on the submit query, it returns email as false, but not anything else. It also will still submit the form. How do I fix this?
JSFiddle: http://jsfiddle.net/GVQpL/
JavaScript Code:
function validateForm(/*fullName, email, phoneNumber*/)
{
//-------------------------NAME VALIDATION-----------------------------//
var fullNameV = document.forms["queryForm"]["fullName"].value;
if (fullNameV == null || fullNameV == "")
{
alert("Name must be filled out!");
return false;
}
else if(fullNameV.indexOf(" ") <= fullNameV.length)
{
alert("Not a valid name");
return false;
}
//-------------------------EMAIL VALIDATION-----------------------------//
var emailV = document.forms["queryForm"]["email"].value;
if (emailV == null || emailV == "")
{
alert("Email must be filled out!");
return false;
}
var atpos = emailV.indexOf("#");
var dotpos = emailV.lastIndexOf(".");
if (atpos < 1 || dotpos < atpos + 2 || dotpos + 2 >= x.length)
{
alert("Not a valid e-mail address");
return false;
}
//-------------------------PHONE # VALIDATION-----------------------------//
var phoneNumberV = document.forms["queryForm"]["phoneNumber"].value;
if (phoneNumberV == null || phoneNumberV == "")
{
alert("Phone Number must be filled out!");
return false;
}
var error = "";
var stripped = phoneNumberV.replace(/[\(\)\.\-\ ]/g, '');
if (phoneNumberV == "")
{
error = alert("You didn't enter a phone number.\n");
phoneNumberV.style.background = 'Yellow';
}
else if (isNaN(parseInt(stripped)))
{
error = alert("The phone number contains illegal characters.\n");
phoneNumberV.style.background = 'Yellow';
}
else if (!(stripped.length == 10))
{
error = alert("The phone number is the wrong length. Make sure you included an area code.\n");
phoneNumberV.style.background = 'Yellow';
}
return error;
}
Update your fiddle's html for the function to be called onsubmit="return validateForm()" and removed the required="required" changed your function to work, you can see it here:
http://jsfiddle.net/GVQpL/3/
function validateForm(/*fullName, email, phoneNumber*/)
{
//-------------------------NAME VALIDATION-----------------------------//
var fullNameV = document.forms["queryForm"]["fullName"].value;
if (fullNameV == null || fullNameV == "")
{
alert("Name must be filled out!");
document.forms["queryForm"]["fullName"].focus();
return false;
}
else if(fullNameV.indexOf(" ") >= fullNameV.length)
{
alert("Not a valid name");
document.forms["queryForm"]["fullName"].focus();
return false;
}
//-------------------------EMAIL VALIDATION-----------------------------//
var emailV = document.forms["queryForm"]["email"].value;
if (emailV == null || emailV == "")
{
alert("Email must be filled out!");
document.forms["queryForm"]["email"].focus();
return false;
}
var emailReg = /^([\w-\.]+#([\w-]+\.)+[\w-]{2,4})?$/;
if(!emailReg.test(emailV)){
alert("Not a valid e-mail address");
document.forms["queryForm"]["email"].focus();
return false;
}
//-------------------------PHONE # VALIDATION-----------------------------//
var phoneNumberV = document.forms["queryForm"]["phoneNumber"].value;
if (phoneNumberV == null || phoneNumberV == "")
{
alert("Phone Number must be filled out!");
document.forms["queryForm"]["phoneNumber"].focus();
return false;
}
var error = "";
var stripped = phoneNumberV.replace(/[\(\)\.\-\ ]/g, '');
if (phoneNumberV == "")
{
alert("You didn't enter a phone number.\n");
document.forms["queryForm"]["phoneNumber"].focus()
document.forms["queryForm"]["phoneNumber"].style.background = 'Yellow';
return false;
}
else if (isNaN(parseInt(stripped)))
{
alert("The phone number contains illegal characters.\n");
document.forms["queryForm"]["phoneNumber"].focus();
document.forms["queryForm"]["phoneNumber"].style.background = 'Yellow';
return false;
}
else if (!(stripped.length == 10))
{
alert("The phone number is the wrong length. Make sure you included an area code.\n");
document.forms["queryForm"]["phoneNumber"].focus();
document.forms["queryForm"]["phoneNumber"].style.background = 'Yellow';
return false;
}
if(!confirm('Are you sure you want to submit your DSLR query?')){
return false;
}
return true;
}

How to validate multiple fields at the same time using JQuery

I have created a form that validates using JQuery and JavaScript. The only problem is, would be that it validates one field at a time. So the user has to correct the first field first and then press submit again to see if the next field is valid.
What I would like to to do, is have the JQuery validate the whole form after pressing submit and show all the applicable error messages.
Here is My JS:
function validateUserName()
{
var u = document.forms["NewUser"]["user"].value
var uLength = u.length;
var illegalChars = /\W/; // allow letters, numbers, and underscores
if (u == null || u == "")
{
$("#ErrorUser").text("You Left the Username field Emptyyy");
return false;
}
else if (uLength < 4 || uLength > 11)
{
$("#ErrorUser").text("The Username must be between 4 and 11 characters");
return false;
}
else if (illegalChars.test(u))
{
$("#ErrorUser").text("The Username contains illegal charectors men!");
return false;
}
else
{
return true;
}
}
function validatePassword()
{
var p = document.forms["NewUser"]["pwd"].value
var cP = document.forms["NewUser"]["confirmPwd"].value
var pLength = p.length;
if (p == null || p == "")
{
$("#ErrorPassword1").text("You left the password field empty");
return false;
}
else if (pLength < 6 || pLength > 20)
{
$("#ErrorPassword1").text("Your password must be between 6 and 20 characters in length");
return false;
}
else if (p != cP)
{
$("#ErrorPassword1").text("Th passwords do not match!");
return false;
}
else
{
return true;
}
}
function validateEmail()
{
var e = document.forms["NewUser"]["email"].value
var eLength = e.length;
var emailFilter = /^[^#]+#[^#.]+\.[^#]*\w\w$/;
var illegalChars = /[\(\)\<\>\,\;\:\\\"\[\]]/;
if (eLength == "" || eLength == null)
{
$("#ErrorEmail").text("You left the email field blank!");
return false;
}
else if (e.match(illegalChars))
{
$("#ErrorEmail").text("ILEGAL CHARECTORS DETECTED EXTERMINATE");
return false;
}
else
{
return true;
}
}
function validateFirstName()
{
var f = document.forms["NewUser"]["fName"].value;
var fLength = f.length;
var illegalChars = /\W/;
if (fLength > 20)
{
$("#ErrorFname").text("First Name has a max of 20 characters");
return false;
}
else if (illegalChars.test(f))
{
$("#ErrorFname").text("Numbers,letter and underscores in first name only");
return false;
}
else
{
return true;
}
}
function validateLastName()
{
var l = document.forms["NewUser"]["lName"].value;
var lLength = l.length;
var illegalChars = /\W/;
if (lLength > 100)
{
$("#ErrorLname").text("Last Name has a max of 100 characters");
return false;
}
else if (illegalChars.test(f))
{
$("#ErrorLname").text("Numbers,letter and underscores in last name only");
return false;
}
else
{
return true;
}
}
function validateForm()
{
valid = true;
//call username function
valid = valid && validateUserName();
//call password function
valid = valid && validatePassword();
//call email function
valid = valid && validateEmail();
//call first name function
valid = valid && validateFirstName();
//call first name function
valid = valid && validateLastName();
return valid;
}
And here is my submit form code:
$('#your-form').submit(validateForm);
Instead of returning true or false return a string containing the error and an empty string if no error was found.
Then validateForm could be something like
function validateForm()
{
error = "";
//call username function
error += "\n"+validateUserName();
//call password function
error += "\n"+validatePassword();
...
if(error === ""){
return true;
}
$("#ErrorLname").text(error);
return false;
}
Working Fiddle
var validate;
function validateUserName()
{
validate = true;
var u = document.forms["NewUser"]["user"].value
var uLength = u.length;
var illegalChars = /\W/; // allow letters, numbers, and underscores
if (u == null || u == "")
{
$("#ErrorUser").text("You Left the Username field Emptyyy");
validate = false;
}
else if (uLength <4 || uLength > 11)
{
$("#ErrorUser").text("The Username must be between 4 and 11 characters");
validate = false;
}
else if (illegalChars.test(u))
{
$("#ErrorUser").text("The Username contains illegal charectors men!");
validate = false;
}
}
function validatePassword()
{
var p = document.forms["NewUser"]["pwd"].value
var cP = document.forms["NewUser"]["confirmPwd"].value
var pLength = p.length;
if (p == null || p == "")
{
$("#ErrorPassword1").text("You left the password field empty");
validate = false;
}
else if (pLength < 6 || pLength > 20)
{
$("#ErrorPassword1").text("Your password must be between 6 and 20 characters in length");
validate = false;
}
else if (p != cP)
{
$("#ErrorPassword1").text("Th passwords do not match!");
validate = false;
}
}
function validateEmail()
{
var e = document.forms["NewUser"]["email"].value
var eLength = e.length;
var emailFilter = /^[^#]+#[^#.]+\.[^#]*\w\w$/ ;
var illegalChars= /[\(\)\<\>\,\;\:\\\"\[\]]/ ;
if (eLength == "" || eLength == null)
{
$("#ErrorEmail").text("You left the email field blank!");
validate = false;
}
else if (e.match(illegalChars))
{
$("#ErrorEmail").text("ILEGAL CHARECTORS DETECTED EXTERMINATE");
validate = false;
}
}
function validateFirstName()
{
var f = document.forms["NewUser"]["fName"].value;
var fLength = f.length;
var illegalChars = /\W/;
if(fLength > 20)
{
$("#ErrorFname").text("First Name has a max of 20 characters");
validate = false;
}
else if (illegalChars.test(f))
{
$("#ErrorFname").text("Numbers,letter and underscores in first name only");
validate = false;
}
}
function validateLastName()
{
var l = document.forms["NewUser"]["lName"].value;
var lLength = l.length;
var illegalChars = /\W/;
if(lLength > 100)
{
$("#ErrorLname").text("Last Name has a max of 100 characters");
validate = false;
}
else if (illegalChars.test(f))
{
$("#ErrorLname").text("Numbers,letter and underscores in last name only");
validate = false;
}
}
function validateForm()
{
validateUserName();
validatePassword();
validateEmail();
validateFirstName();
validateLastName();
return validate;
}
You need to access all the fields and check if the field is valid r not. If the field is valid skip it, otherwise put the field in an array. When all the fields have been checked, then display the error fields from the array all at one time.

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