Delete default value of an input text on click

问题:

I have an input text :

<input name="Email" type="text" id="Email" value="[e-mail]" />

I want to put a default value like "What's your programming question ? be specific." in StackOverFlow, and when the user click on it the default value disapear.

回答1:

For future reference, I have to include the HTML5 way to do this.

<input name="Email" type="text" id="Email" value="[e-mail]" placeholder="What's your programming question ? be specific." />

If you have a HTML5 doctype and a HTML5-compliant browser, this will work. However, many browsers do not currently support this, so at least Internet Explorer users will not be able to see your placeholder. However, see http://www.kamikazemusic.com/quick-tips/jquery-html5-placeholder-fix/ (archive.org version) for a solution. Using that, you'll be very modern and standards-compliant, while also providing the functionality to most users.

Also, the provided link is a well-tested and well-developed solution, which should work out of the box.

回答2:

EDIT: Although, this solution works, I would recommend you try MvanGeest's solution below which uses the placeholder-attribute and a javascript fallback for browsers which don't support it yet.

If you are looking for a Mootools equivalent to the JQuery fallback in MvanGeest's reply, here is one.

--

You should probably use onfocus and onblur events in order to support keyboard users who tab through forms.

Here's an example:

<input type="text" value="[e-mail]" name="Email" id="Email"
 onblur="if (this.value == '') {this.value = '[e-mail]';}"
 onfocus="if (this.value == '[e-mail]') {this.value = '';}" />

回答3:

This is somewhat cleaner, i think. Note the usage of the "defaultValue" property of the input:

<script>
function onBlur(el) {
    if (el.value == '') {
        el.value = el.defaultValue;
    }
}
function onFocus(el) {
    if (el.value == el.defaultValue) {
        el.value = '';
    }
}
</script>
<form>
<input type="text" value="[some default value]" onblur="onBlur(this)" onfocus="onFocus(this)" />
</form>

回答4:

Using jQuery, you can do:

$("input:text").each(function ()
{
    // store default value
    var v = this.value;

    $(this).blur(function ()
    {
        // if input is empty, reset value to default 
        if (this.value.length == 0) this.value = v;
    }).focus(function ()
    {
        // when input is focused, clear its contents
        this.value = "";
    }); 
});

And you could stuff all this into a custom plug-in, like so:

jQuery.fn.hideObtrusiveText = function ()
{
    return this.each(function ()
    {
        var v = this.value;

        $(this).blur(function ()
        {
            if (this.value.length == 0) this.value = v;
        }).focus(function ()
        {
            this.value = "";
        }); 
    });
};

Here's how you would use the plug-in:

$("input:text").hideObtrusiveText();

Advantages to using this code is:

• Its unobtrusive and doesn't pollute the DOM
• Code re-use: it works on multiple fields
• It figures out the default value of inputs by itself

Non-jQuery approach:

function hideObtrusiveText(id)
{
    var e = document.getElementById(id);

    var v = e.value;

    e.onfocus = function ()
    {
        e.value = "";
    };

    e.onblur = function ()
    {
        if (e.value.length == 0) e.value = v;
    };
}

回答5:

Enter the following inside the tag, just add onFocus="value=''" so that your final code looks like this:

<input type="email" id="Email" onFocus="value=''"> 

This makes use of the javascript onFocus() event holder.

回答6:

Just use a placeholder tag in your input instead of value

回答7:

we can do it without using js in the following way using the "placeholder" attribute of html5 ( the default text disappears when the user starts to type in ,but not on just clicking )

<input type="email" id="email" placeholder="[e-mail]">

see this: http://www.w3schools.com/html/tryit.asp?filename=tryhtml5_input_placeholder

回答8:

<input name="Email" type="text" id="Email" placeholder="enter your question" />

The placeholder attribute specifies a short hint that describes the expected value of an input field (e.g. a sample value or a short description of the expected format).

The short hint is displayed in the input field before the user enters a value.

Note: The placeholder attribute works with the following input types: text, search, url, tel, email, and password.

I think this will help.

回答9:

Here is very simple javascript. It works fine for me :

function sFocus (field) {
    if(field.value == 'Enter your search') {
        field.value = '';
    }
    field.className = "darkinput";
}

function sBlur (field) {
    if (field.value == '') {
        field.value = 'Enter your search';
        field.className = "lightinput";
    }
    else {
        field.className = "darkinput";
    }
}

回答10:

Why remove value? its useful, but why not try CSS

input[submit] {
   font-size: 0 !important;
}

Value is important to check & validate ur PHP

回答11:

Here is a jQuery solution. I always let the default value reappear when a user clears the input field.

<input name="Email" value="What's your programming question ? be specific." type="text" id="Email" value="[e-mail]" />

<script>
$("#Email").blur(
    function (){
        if ($(this).val() == "")
            $(this).val($(this).prop("defaultValue"));
        }
).focus(
    function (){
        if ($(this).val() == $(this).prop("defaultValue"))
            $(this).val("");
    }
);
</script>

回答12:

I didn't see any really simple answers like this one, so maybe it will help someone out.

var inputText = document.getElementById("inputText");
inputText.onfocus = function(){ if (inputText.value != ""){ inputText.value = "";}; }
inputText.onblur = function(){ if (inputText.value != "default value"){ inputText.value = "default value";}; }

回答13:

Here is an easy way.

#animal represents any buttons from the DOM.
#animal-value is the input id that being targeted.

$("#animal").on('click', function(){
    var userVal = $("#animal-value").val(); // storing that value
    console.log(userVal); // logging the stored value to the console
    $("#animal-value").val('') // reseting it to empty
});