<html>
  <head>
    <meta charset="utf-8">
    <title>Password Tutorial</title>
    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.css">
    <link rel="stylesheet" href="style.css">
    <script type="text/javascript" src="script.js"></script>
  </head>
  <body>
    <div class="container">
      
      <div class="second-example">
        <input type="password" id="password-2" onkeyup="validate();">
      </div>
      
      <div id="validation-txt">
      </div>
    </div>

  </body>
</html>
html, body {
  height: 100%;
  background: #212121;
  margin: 0px;
}
.first-example , .second-example, .third-example{
  margin-bottom: 10px;
}
body {
  align-items: center;
  justify-content: center;
  display: flex;
}

input {
  width: 250px;
  padding: 15px 12px;
  font-size:22px;
}
.fa{
  color:white;
  font-size:27px;
  margin-left:8px;
}
#validation-txt{
  color:red;
  font-size:18px;
  width: 300px;
}
#password-3{
  -webkit-text-security: disc;
    -moz-text-security:circle;
     text-security:circle;
}
input[type=number]::-webkit-inner-spin-button, 
input[type=number]::-webkit-outer-spin-button { 
  -webkit-appearance: none; 
  margin: 0; 
}

function validate(){
  var  validationField = document.getElementById('validation-txt');
  var  password= document.getElementById('password-2');

  var content = password.value;
  var  errors = [];
  console.log(content);
  if (content.length < 8) {
    errors.push("Your password must be at least 8 characters"); 
  }
  if (content.search(/[a-z]/i) < 0) {
    errors.push("Your password must contain at least one letter.");

  }
  if (content.search(/[0-9]/i) < 0) {
    errors.push("Your password must contain at least one digit."); 

  }
  if (errors.length > 0) {
    validationField.innerHTML = errors.join('');

    return false;
  }
    validationField.innerHTML = errors.join('');
    return true;

  }

External CSS

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External JavaScript

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