javascript - Validating email using indexOf() - Stack Overflow

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I am trying to make a sign-up form that will do client-side validation (check the correct layout of email and matching passwords) before sending any data to the server. I have been having trouble checking to see if the email is in the correct form. I can't get the if(email.indexOf(@))to work correctly. I think I misused the .indexOf()

This is my JavaScript:

function sign_check() {
var email = document.getElementById("sign_email").value;
var user = document.getElementById("sign_user").value;
var pass = document.getElementById("sign_pass").value;
var passcon = document.getElementById("sign_confirm").value;

if(pass !== passcon){
  document.getElementById("sign_alert").innerHTML="The passwords do not match"
}

//This part determines whether or not to send the data to the server
if(email.length >= 7){
  if(email.indexOf("@")){
    if(user.length >= 1){
      if(pass.length >= 1){
        if(passcon.length >= 1){
          if(pass === passcon){
            alert("All of the requirements have been met")
          }
        }
      }
    }
  }
}
}

And this is my html:

  <h1 id="pop_up" class="pop_up">Sign Up</h1>

  <form id="sign_up" class="sign_up">
  <label id="alert_s1" class="alert">  <br />  </label>
    <input id="sign_email" class="sign" type="text" placeholder="Email" name="sign_email" /><br />
      <label id="alert_s2" class="alert">  <br />  </label>
    <input id="sign_user" class="sign" type="text" placeholder="Username" name="sign_user" /><br />
      <label id="alert_s3" class="alert">  <br />  </label>
    <input id="sign_pass" class="sign" type="text" placeholder="Password" name="sign_pass" /><br />
      <label id="alert_s4" class="alert">  <br />  </label>
    <input id="sign_confirm" class="sign" type="text" placeholder="Confirm Password" name="sign_confirm" />
  </form>

  <p id="sign_alert" class="alert"></p>

  <button onclick="sign_check()">Submit</button>

  <a href="javascript:void(0)" class="pop_up" id="pop_up" onclick="document.getElementById('sign_box').style.display='none'; document.getElementById('log_box').style.display='block'">Already have an acount? Click here to log in.</a>
</div>

I am trying to make a sign-up form that will do client-side validation (check the correct layout of email and matching passwords) before sending any data to the server. I have been having trouble checking to see if the email is in the correct form. I can't get the if(email.indexOf(@))to work correctly. I think I misused the .indexOf()

This is my JavaScript:

function sign_check() {
var email = document.getElementById("sign_email").value;
var user = document.getElementById("sign_user").value;
var pass = document.getElementById("sign_pass").value;
var passcon = document.getElementById("sign_confirm").value;

if(pass !== passcon){
  document.getElementById("sign_alert").innerHTML="The passwords do not match"
}

//This part determines whether or not to send the data to the server
if(email.length >= 7){
  if(email.indexOf("@")){
    if(user.length >= 1){
      if(pass.length >= 1){
        if(passcon.length >= 1){
          if(pass === passcon){
            alert("All of the requirements have been met")
          }
        }
      }
    }
  }
}
}

And this is my html:

  <h1 id="pop_up" class="pop_up">Sign Up</h1>

  <form id="sign_up" class="sign_up">
  <label id="alert_s1" class="alert">  <br />  </label>
    <input id="sign_email" class="sign" type="text" placeholder="Email" name="sign_email" /><br />
      <label id="alert_s2" class="alert">  <br />  </label>
    <input id="sign_user" class="sign" type="text" placeholder="Username" name="sign_user" /><br />
      <label id="alert_s3" class="alert">  <br />  </label>
    <input id="sign_pass" class="sign" type="text" placeholder="Password" name="sign_pass" /><br />
      <label id="alert_s4" class="alert">  <br />  </label>
    <input id="sign_confirm" class="sign" type="text" placeholder="Confirm Password" name="sign_confirm" />
  </form>

  <p id="sign_alert" class="alert"></p>

  <button onclick="sign_check()">Submit</button>

  <a href="javascript:void(0)" class="pop_up" id="pop_up" onclick="document.getElementById('sign_box').style.display='none'; document.getElementById('log_box').style.display='block'">Already have an acount? Click here to log in.</a>
</div>

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Share Improve this question Follow asked Mar 9, 2014 at 0:06 justephensjustephens 311 gold badge11 silver badge22 bronze badges 5

• 2 0 is a valid index, and -1 is returned on failure, so: email.indexOf("@") !== -1 Or do > 0 if you want to ensure that @ isn't the first character. – cookie monster Commented Mar 9, 2014 at 0:08
• holy nested if statements, batman! – PlantTheIdea Commented Mar 9, 2014 at 0:09
• 4 How bout just /^\S+@\S+\.\S+$/.test(email) – adeneo Commented Mar 9, 2014 at 0:09
• Not a fan of the && operator? – leigero Commented Mar 9, 2014 at 0:11
• 1 Link to a better way to validate e-mail in JavaScript stackoverflow./questions/46155/… It's only got 827 points, who knows... – Brian Hoover Commented Mar 9, 2014 at 0:12

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2 Answers 2

Sorted by: Reset to default 3

First, your method to validate the email is not very accurate :) Besides that, you're using indexOf incorrectly. Use this instead.

if(email.indexOf("@") != -1 )

You used double quotes "" instead of '' in the ('@'). That should make it work. And === actually works too. The quotation marks were all you needed to change. I hope this helps!

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