使用jquery验证表单输入字段

$(document).ready(function() {

  /* contact form validation */
  var Validator = function(formObject) {
    this.form = $(formObject);
    var Elements = {
      name: {
        reg: /^[a-zA-Z ]{2,20}$/,
        require: true,
        error: "Not a valid name.",
      },

      email: {
        reg: /^[a-z-0-9_+.-]+\@([a-z0-9-]+\.)+[a-z0-9]{2,7}$/i,
        error: "Not a valid e-mail address.",
      },
      phone: {
        reg: /^\(?([0-9]{3})\)?[-. ]?([0-9]{3})[-. ]?([0-9]{4})$/,
        error: "Not a valid number.",
      },

      message: {
        reg: /^(?!\s*$).+/,
        error: "Message field cannot be empty.",
      },
      gender: {
        error: "gender is required",
      },
      selectOption: {
        error: "this field is required",
        required: true
      }
    };

    var handleError = function(element, message) {
      element.addClass('input-error');
      var $err_msg = element.parent('div');
      $err_msg.find('.error').remove();

      var error = $('<div class="error"></div>').text(message);
      error.appendTo($err_msg);
      console.log(element);


      element.on('keypress change', function() {
        $(error).fadeOut(1000, function() {
          console.log(element);
          element.removeClass('input-error');
        });
      });

    };

    /* Select Option */

    this.validate = function() {
      var errorCount = 0;

      this.form.find("select").each(function(index, field) {
        var type = $(field).data("validation");
        var validation = Elements[type];
        if ($(field).val() == "") {
          errorCount++;
          handleError($(field), validation.error);
        }
      });

      this.form.find("input, textarea").each(function(index, field) {
        var type = $(field).data("validation");
        var validation = Elements[type];
        if (validation !== undefined) {
          var re = new RegExp(validation.reg);
          if (validation) {
            if (!re.test($(field).val())) {
              errorCount++;
              handleError($(field), validation.error);
            }
          }
        }
      })

      /* Radio button */

      var radioList = $('input:radio');
      var radioNameList = new Array();
      var radioUniqueNameList = new Array();
      var notCompleted = 0;
      for (var i = 0; i < radioList.length; i++) {
        radioNameList.push(radioList[i].name);
      }
      radioUniqueNameList = jQuery.unique(radioNameList);
      console.log(radioUniqueNameList);
      for (var i = 0; i < radioUniqueNameList.length; i++) {
        var field = $('#' + radioUniqueNameList[i]);
        var type = field.data("validation");
        var validation = Elements[type];
        if ($('input[name=' + type + ']:checked', '#test').val() == undefined) {
          errorCount++;
          handleError($(field), validation.error);
        }
      }

      return errorCount == 0;
    };
  };

  /* Submit form*/

  $(function() {

    $("form#test").on('submit', function(e) {
      var NoErrors = new Validator(this).validate();
      if (NoErrors == true) {
        $.ajax({
          url: this.action,
          type: this.method,
          data: $(this).serialize(),
          success: function() {
            // AJAX request finished, handle the results and error msg
            $('.success_msg').fadeIn().delay(3000).fadeOut();
            $('input[type!="submit"], textarea').val('').removeClass('error');
          }
        });

      }
      return false;
    })

  })

});

body {
  background: #fff;
  color: #333;
  font: 76% Verdana, sans-serif;
}

form {
  margin: 1em 0 0 2em;
  width: 90%;
}

fieldset {
  margin: 0;
  border: 1px solid #ccc;
  padding-bottom: 1em;
}

legend {
  font-weight: bold;
  text-transform: uppercase;
}

label {
  float: left;
  width: 5em;
  padding-right: 2em;
  font-weight: bold;
}

div {
  margin-bottom: 30px;
}

input {
  font: 1em Verdana, sans-serif;
}

fieldset ul li input {
  float: left;
  width: 120px;
  border: 1px solid #ccc;
}

textarea {
  width: 300px;
  height: 200px;
  border: 1px solid #ccc;
  font: 1em Verdana, sans-serif;
}

form p {
  margin: 0;
  padding: 0.4em 0 0 7em;
}

form p input {
  background: #666;
  color: #fff;
  font-weight: bold;
}

div.error {
  clear: left;
  margin-left: 5.3em;
  color: red;
  padding-right: 1.3em;
  height: 100%;
  padding-bottom: 0.3em;
  line-height: 1.3;
}

.input-error {
  background: #ff9;
  border: 1px solid red;
}

.success_msg {
  width: 350px;
  line-height: 40px;
  border: 1px solid green;
  border-radius: 5px;
  background-color: rgba(213, 255, 187, 0.7);
  display: none;
  position: absolute;
  bottom: 5px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 999;
  text-align: center;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.0/jquery.min.js"></script>
<form action="#" method="post" id="test">
  <fieldset>

    <legend>Contact information</legend>


    <div>
      <label for="firstname">Firstname:</label>
      <input type="text" name="firstname" id="firstname" data-validation="name" />
    </div>


    <div>
      <label for="lastname">Lastname:</label>
      <input type="text" name="lastname" id="lastname" data-validation="name" />
    </div>

    <div>
      <label for="email">Email:</label>
      <input type="email" name="email" id="email" data-validation="email" />

    </div>
    <div>
      <label for="phone">phone</label>
      <input type="number" name="phone" id="phone" data-validation="phone" />
    </div>

    <div>
      <label>Gender:</label>
      <input type="radio" name="gender" value="male" data-validation="gender" />
      <input type="radio" name="gender" value="female" data-validation="gender">
    </div>

    <select data-validation="selectOption">
      <option value="">Select any option</option>
      <option value="red">Red</option>
      <option value="blue">Blue</option>
      <option value="green">Green</option>
    </select>

    <div>
      <label for="message">Message:</label>
      <textarea id="message" name="message" cols="30" rows="15" data-validation="message"></textarea>
    </div>

    <p><input type="submit" name="send" id="send" value="Send" /></p>

  </fieldset>
  <div class="success_msg">
    <p>Form submitted Successfully</p>
  </div>
</form>