How to show a required message next to input with Javascript? [duplicate]

问题

I'm trying to make fields required but I want the error to show up next to the field it self not be alert?

回答1:

You can put validation messages near inputs you wanna validate like

<span class="reqMsg">* First name is required</span>

Of course you need to hide them at first with css

.reqMsg {
   color:red;
   display:none;
}

Then in your form submit function you can change your relevant code to this

var valid = true;
var firstFocus = null;
for (var i = 0; i < rules.length; i++) {
   if (!rules[i][1]) {
      valid = false;
      var parent = elem(rules[i][0]).parentNode;
      parent.children[2].style.display = "inline";
      if (firstFocus == null) firstFocus = parent.children[1];
   }
}
if (!valid) {
   firstFocus.focus();
   return false;
}
return true;

You can see that it's not returning false immediately if one field is not valid. It checks all the fields then set a focus to first element of those that are not valid.

FIDDLE

回答2:

Add span tag next to input tag

<span id="first-name-err"></span>

and change you javascript code as below

function alpha(e) {
        var k;
        document.all ? k = e.keyCode : k = e.which;
        return ((k > 64 && k < 91) || (k > 96 && k < 123) || k == 8);
    }
    var flag = true;
    for (var i = 0; i < rules.length; i++) {
        alert(rules[i][0]);
        if (!rules[i][1]) {
            var parent = elem(rules[i][0]).parentNode,
                message = 'Please check your ' + (parent.textContent || parent.innerText).replace(/^\s*(.*?)\s*$/, '$1').slice(0, -1).toLowerCase() + '.';
                var id = rules[i][0]+'-err';
    document.getElementById(rules[i][0]+'-err').innerHTML = message;
           flag = false;
        }
    }
    return flag;
};

check this

来源：https://stackoverflow.com/questions/23510490/how-to-show-a-required-message-next-to-input-with-javascript

标签

javascript

jquery

html

validation

xhtml