<input>
elements of type
email
are used to let the user enter and edit an e-mail address, or, if the
multiple
attribute is specified, a list of e-mail addresses.
The input value is automatically validated to ensure that it's either empty or a properly-formatted e-mail address (or list of addresses) before the form can be submitted. The
:valid
and
:invalid
CSS pseudo-classes are automatically applied as appropriate to visually denote whether the current value of the field is a valid e-mail address or not.
On browsers that don't support inputs of type
email
，
email
input falls back to being a standard
text
输入。
| 值 |
A
DOMString
representing an e-mail address, or empty
|
| 事件 |
change
and
input
|
| Supported Common Attributes |
autocomplete
,
list
,
maxlength
,
minlength
,
multiple
,
name
,
pattern
,
placeholder
,
readonly
,
required
,
size
，和
type
|
| IDL attributes |
list
and
value
|
| 方法 |
select()
|
<input>
元素的
value
attribute contains a
DOMString
which is automatically validated as conforming to e-mail syntax. More specifically, there are three possible value formats that will pass validation:
username@domain
or
username@domain.tld
. There's more to it than that, of course; see
验证
对于
regular expression
that matches the e-mail address validation algorithm.
multiple
attribute is specified, the value can be a list of properly-formed comma-separated e-mail addresses. Any trailing and leading whitespace is removed from each address in the list.
见 验证 for details on how e-mail addresses are validated to ensure that they're formatted properly.
In addition to the attributes that operate on all
<input>
elements regardless of their type,
email
inputs support the following attributes:
| 属性 | 描述 |
|---|---|
list
|
The id of the <datalist> element that contains the optional pre-defined autocomplete options |
maxlength
|
The maximum number of characters the input should accept |
minlength
|
The minimum number of characters long the input can be and still be considered valid |
multiple
|
Whether or not to allow multiple, comma-separated, e-mail addresses to be entered |
pattern
|
A regular expression the input's contents must match in order to be valid |
placeholder
|
An exemplar value to display in the input field whenever it is empty |
readonly
|
A Boolean attribute indicating whether or not the contents of the input should be read-only |
size
|
A number indicating how many characters wide the input field should be |
list
The values of the list attribute is the
id
的
<datalist>
element located in the same document. The
<datalist>
provides a list of predefined values to suggest to the user for this input. Any values in the list that are not compatible with the
type
are not included in the suggested options. The values provided are suggestions, not requirements: users can select from this predefined list or provide a different value.
maxlength
The maximum number of characters (as UTF-16 code units) the user can enter into the
email
input. This must be an integer value 0 or higher. If no
maxlength
is specified, or an invalid value is specified, the
email
input has no maximum length. This value must also be greater than or equal to the value of
minlength
.
The input will fail
constraint validation
if the length of the text value of the field is greater than
maxlength
UTF-16 code units long. Constraint validation is only applied when the value is changed by the user.
minlength
The minimum number of characters (as UTF-16 code units) the user can enter into the
email
input. This must be an non-negative integer value smaller than or equal to the value specified by
maxlength
. If no
minlength
is specified, or an invalid value is specified, the
email
input has no minimum length.
The input will fail
constraint validation
if the length of the text entered into the field is fewer than
minlength
UTF-16 code units long. Constraint validation is only applied when the value is changed by the user.
multiple
A Boolean attribute which, if present, indicates that the user can enter a list of multiple e-mail addresses, separated by commas and, optionally, whitespace characters. See Allowing multiple e-mail addresses for an example, or HTML attribute: multiple 了解更多细节。
注意：
Normally, if you specify the
required
attribute, the user must enter a valid e-mail address for the field to be considered valid. However, if you add the
multiple
attribute, a list of zero e-mail addresses (an empty string, or one which is entirely whitespace) is a valid value. In other words, the user does not have to enter even one e-mail address when
multiple
is specified, regardless of the value of
required
.
pattern
pattern
attribute, when specified, is a regular expression that the input's
value
must match in order for the value to pass
constraint validation
. It must be a valid JavaScript regular expression, as used by the
RegExp
type, and as documented in our
guide on regular expressions
；
'u'
flag is specified when compiling the regular expression, so that the pattern is treated as a sequence of Unicode code points, instead of as ASCII. No forward slashes should be specified around the pattern text.
If the specified pattern is not specified or is invalid, no regular expression is applied and this attribute is ignored completely.
提示：
使用
title
attribute to specify text that most browsers will display as a tooltip to explain what the requirements are to match the pattern. You should also include other explanatory text nearby.
See the section Pattern validation for details and an example.
placeholder
placeholder
attribute is a string that provides a brief hint to the user as to what kind of information is expected in the field. It should be a word or short phrase that demonstrates the expected type of data, rather than an explanatory message. The text
不必
include carriage returns or line feeds.
If the control's content has one directionality ( LTR or RTL ) but needs to present the placeholder in the opposite directionality, you can use Unicode bidirectional algorithm formatting characters to override directionality within the placeholder; see Overriding BiDi using Unicode control characters in The Unicode Bidirectional Text Algorithm for those characters.
注意：
Avoid using the
placeholder
attribute if you can. It is not as semantically useful as other ways to explain your form, and can cause unexpected technical issues with your content. See
Labels and placeholders
in
<input>: The Input (Form Input) element
了解更多信息。
readonly
A Boolean attribute which, if present, means this field cannot be edited by the user. Its
value
can, however, still be changed by JavaScript code directly setting the
HTMLInputElement.value
特性。
注意：
Because a read-only field cannot have a value,
required
does not have any effect on inputs with the
readonly
attribute also specified.
size
size
attribute is a numeric value indicating how many characters wide the input field should be. The value must be a number greater than zero, and the default value is 20. Since character widths vary, this may or may not be exact and should not be relied upon to be so; the resulting input may be narrower or wider than the specified number of characters, depending on the characters and the font (
font
settings in use).
This does
not
set a limit on how many characters the user can enter into the field. It only specifies approximately how many can be seen at a time. To set an upper limit on the length of the input data, use the
maxlength
属性。
E-mail addresses are among the most frequently-inputted textual data forms on the web; they're used when logging into web sites, when requesting information, to allow order confirmation, for webmail, and so forth. As such, the
email
input type can make your job as a web developer much easier since it can help simplify your work when building the user interface and logic for e-mail addresses. When you create an email input with the proper
type
值，
email
, you get automatic validation that the entered text is at least in the correct form to potentially be a legitimate e-mail address. This can help avoid cases in which the user mistypes their address, or provides an invalid address.
It's important, however, to note that this is not enough to ensure that the specified text is an e-mail address which actually exists, corresponds to the user of the site, or is acceptable in any other way. It simply ensures that the value of the field is properly formatted to be an e-mail address.
注意 : It's also crucial to remember that a user can tinker with your HTML behind the scenes, so your site 不必 use this validation for any security purposes. You must verify the e-mail address on the server side of any transaction in which the provided text may have any security implications of any kind.
Currently, all browsers which implement this element implement it as a standard text input field with basic validation features. The specification does, however, allow browsers latitude on this. For example, the element could be integrated with the user's device's built-in address book to allow picking e-mail addresses from that list. In its most basic form, an
email
input can be implemented like this:
<input id="emailAddress" type="email">
Notice that it's considered valid when empty and when a single validly-formatted e-mail address is entered, but is otherwise not considered valid. By adding the
required
attribute, only validly-formed e-mail addresses are allowed; the input is no longer considered valid when empty.
By adding the
multiple
Boolean attribute, the input can be configured to accept multiple e-mail addresses.
<input id="emailAddress" type="email" multiple>
The input is now considered valid when a single e-mail address is entered, or when any number of e-mail addresses separated by commas and, optionally, some number of whitespace characters are present.
注意
: When
multiple
is used, the value
is
allowed to be empty.
Some examples of valid strings when
multiple
is specified:
""
"me@example"
"me@example.org"
"me@example.org,you@example.org"
"me@example.org, you@example.org"
"me@example.org,you@example.org, us@example.org"
Some examples of invalid strings:
","
"me"
"me@example.org you@example.org"
Sometimes it's helpful to offer an in-context hint as to what form the input data should take. This can be especially important if the page design doesn't offer descriptive labels for each
<input>
. This is where
placeholders
come in. A placeholder is a value that demonstrates the form the
value
should take by presenting an example of a valid value, which is displayed inside the edit box when the element's
value
is "". Once data is entered into the box, the placeholder disappears; if the box is emptied, the placeholder reappears.
Here, we have an
email
input with the placeholder
sophie@example.com
. Note how the placeholder disappears and reappears as you manipulate the contents of the edit field.
<input type="email" placeholder="sophie@example.com">
You can control not only the physical length of the input box, but also the minimum and maximum lengths allowed for the input text itself.
The physical size of the input box can be controlled using the
size
attribute. With it, you can specify the number of characters the input box can display at a time. In this example the
email
edit box is 15 characters wide:
<input type="email" size="15">
size
is separate from the length limitation on the entered e-mail address itself so that you can have fields fit in a small space while still allowing longer e-mail address strings to be entered. You can specify a minimum length, in characters, for the entered e-mail address using the
minlength
attribute; similarly, use
maxlength
to set the maximum length of the entered e-mail address.
The example below creates a 32 character-wide e-mail address entry box, requiring that the contents be no shorter than 3 characters and no longer than 64 characters.
<input type="email" size="32" minlength="3" maxlength="64">
As always, you can provide a default value for an
email
input box by setting its
value
属性：
<input type="email" value="default@example.com">
Taking it a step farther, you can provide a list of default options from which the user can select by specifying the
list
attribute. This doesn't limit the user to those options, but does allow them to select commonly-used e-mail addresses more quickly. This also offers hints to
autocomplete
。
list
attribute specifies the ID of a
<datalist>
, which in turn contains one
<option>
element per suggested value; each
option
's
value
is the corresponding suggested value for the email entry box.
<input type="email" size="40" list="defaultEmails"> <datalist id="defaultEmails"> <option value="jbond007@mi6.defence.gov.uk"> <option value="jbourne@unknown.net"> <option value="nfury@shield.org"> <option value="tony@starkindustries.com"> <option value="hulk@grrrrrrrr.arg"> </datalist>
With the
<datalist>
element and its
<option>
s in place, the browser will offer the specified values as potential values for the e-mail address; this is typically presented as a popup or drop-down menu containing the suggestions. While the specific user experience may vary from one browser to another, typically clicking in the edit box presents a drop-down of the suggested e-mail addresses. Then, as the user types, the list is filtered to show only matching values. Each typed character narrows down the list until the user makes a selection or types a custom value.
There are two levels of content validation available for
email
inputs. First, there's the standard level of validation offered to all
<input>
s, which automatically ensures that the contents meet the requirements to be a valid e-mail address. But there's also the option to add additional filtering to ensure that your own specialized needs are met, if you have any.
重要 : HTML form validation is not a substitute for scripts that ensure that the entered data is in the proper format.It's far too easy for someone to make adjustments to the HTML that allow them to bypass the validation, or to remove it completely. It's also possible for someone to simply bypass your HTML entirely and submit the data directly to your server. If your server-side code fails to validate the data it receives, disaster could strike when improperly-formatted data (or data which is too large, is of the wrong type, and so forth) is entered into your database.
Browsers that support the
email
input type automatically provide validation to ensure that only text that matches the standard format for Internet e-mail addresses is entered into the input box. Browsers that implement the specification should be using an algorithm equivalent to the following regular expression:
/^[a-zA-Z0-9.!#$%&'*+\/=?^_`{|}~-]+@[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}
[a-zA-Z0-9])?(?:\.[a-zA-Z0-9](?:[a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?)*$/
Tolearn more about how form validation works and how to take advantage of the
:valid
and
:invalid
CSS properties to style the input based on whether or not the current value is valid, see
Form data validation
.
注意 : There are known specification issues related to international domain names and the validation of e-mail addresses in HTML. See W3C bug 15489 了解细节。
If you need the entered e-mail address to be restricted further than just "any string that looks like an e-mail address," you can use the
pattern
attribute to specify a
regular expression
the value must match for it to be valid. If the
multiple
attribute is specified, each individual item in the comma-delineated list of values must match the
regular expression
.
For example, let's say you're building a page for employees of Best Startup Ever, Inc. which will let them contact their IT department for help. In our simplified form, the user needs to enter their e-mail address and a message describing the problem they need help with. We want to ensure that not only does the user provide a valid e-mail address, but for security purposes, we require that the address be an internal corporate e-mail address.
Since inputs of type
email
validate against both the standard e-mail address validation
and
指定
pattern
, you can implement this easily. Let's see how:
body {
font: 16px sans-serif;
}
.emailBox {
padding-bottom: 20px;
}
.messageBox {
padding-bottom: 20px;
}
label {
line-height: 22px;
}
label::after {
content: ":";
}
<form>
<div class="emailBox">
<label for="emailAddress">Your e-mail address</label><br>
<input id="emailAddress" type="email" size="64" maxLength="64" required
placeholder="username@beststartupever.com" pattern=".+@beststartupever.com"
title="Please provide only a Best Startup Ever corporate e-mail address">
</div>
<div class="messageBox">
<label for="message">Request</label><br>
<textarea id="message" cols="80" rows="8" required
placeholder="My shoes are too tight, and I have forgotten how to dance."></textarea>
</div>
<input type="submit" value="Send Request">
</form>
我们的
<form>
contains one
<input>
类型
email
for the user's e-mail address, a
<textarea>
to enter their message for IT into, and an
<input>
类型
"submit"
, which creates a button to submit the form. Each text entry box has a
<label>
associated with it to let the user know what's expected of them.
Let's take a closer look at the e-mail address entry box. Its
size
and
maxlength
attributes are both set to 64 in order to show room for 64 characters worth of e-mail address, and to limit the number of characters actually entered to a maximum of 64. The
required
attribute is specified, making it mandatory that a valid e-mail address be provided.
适当
placeholder
is provided—
username@beststartupever.com
—to demonstrate what constitutes a valid entry. This string demonstrates both that an e-mail address should be entered, and suggests that it should be a corporate beststartupever.com account. This is in addition to the fact that using type
email
will validate the text to ensure that it's formatted like an e-mail address. If the text in the input box isn't an e-mail address, you'll get an error message that looks something like this:
If we left things at that, we would at least be validating on legitimate e-mail addresses. But we want to go one step farther: we want to make sure that the e-mail address is in fact in the form "
username
@beststartupever.com". This is where we'll use
pattern
. We set
pattern
to
.+@beststartupever.com
. This simple regular expression requests a string that consists of at least one character of any kind, then an "@" followed by the domain name "beststartupever.com".
Note that this is not even close to an adequate filter for valid e-mail addresses; it would allow things such as " @beststartupever.com" (note the leading space) or "@@beststartupever.com", neither of which is valid. However, the browser runs both the standard e-mail address filter and our custom pattern against the specified text. As a result, we wind up with a validation which says "make sure this resembles a valid e-mail address, and if it is, make sure it's also a beststartupever.com address."
It's advisable to use the
title
attribute along with
pattern
. If you do, the
title
must
describe the pattern. That is, it should explain what format the data should take on, rather than any other information. That's because the
title
may be displayed or spoken as part of a validation error message. For example, the browser might present the message "The entered text doesn't match the required pattern." followed by your specified
title
. If your
title
is something like "E-mail address", the result would be the message "The entered text doesn't match the required pattern. E-mail address", which isn't very good.
That's why, instead, we specify the string "Please provide only a Best Startup Ever corporate e-mail address" By doing that, the resulting full error message might be something like "The entered text doesn't match the required pattern. Please provide only a Best Startup Ever corporate e-mail address."
注意 : If you run into trouble while writing your validation regular expressions and they're not working properly, check your browser's console; there may be helpful error messages there to aid you in solving the problem.
Here we have an email input with the ID
emailAddress
which is allowed to be up to a maximum of 256 characters long. The input box itself is physically 64 characters wide, and displays the text
user@example.gov
as a placeholder anytime the field is empty. In addition, by using the
multiple
attribute, the box is configured to allow the user to enter zero or more e-mail addresses, separated by commas, as described in
Allowing multiple e-mail addresses
. As a final touch, the
list
attribute contains the ID of a
<datalist>
whose
<option>
s specify a set of suggested values the user can choose from.
As an added touch, the
<label>
element is used to establish a label for the email entry box, with its
for
attribute referencing the
emailAddress
ID of the
<input>
element. By associating the two elements in this way, clicking on the label will focus the input element.
<label for="emailAddress">Email</label><br/>
<input id="emailAddress" type="email" placeholder="user@example.gov"
list="defaultEmails" size="64" maxlength="256" multiple>
<datalist id="defaultEmails">
<option value="jbond007@mi6.defence.gov.uk">
<option value="jbourne@unknown.net">
<option value="nfury@shield.org">
<option value="tony@starkindustries.com">
<option value="hulk@grrrrrrrr.arg">
</datalist>
| 规范 | 状态 | 注释 |
|---|---|---|
|
HTML 实时标准
The definition of '<input type="email">' in that specification. |
实时标准 | 初始定义 |
| 桌面 | 移动 | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
type="email"
|
Chrome 完整支持 5 | Edge 完整支持 12 | Firefox 完整支持 Yes | IE 完整支持 10 | Opera 完整支持 11 | Safari 完整支持 Yes | WebView Android ? | Chrome Android ? | Firefox Android 完整支持 4 | Opera Android 完整支持 Yes |
Safari iOS
完整支持
3.1
注意事项
|
Samsung Internet Android ? |
完整支持
兼容性未知
见实现注意事项。
<button>
<datalist>
<fieldset>
<form>
<input>
<label>
<legend>
<meter>
<optgroup>
<option>
<output>
<progress>
<select>
<textarea>
<input>
类型
<input type="button">
<input type="checkbox">
<input type="color">
<input type="date">
<input type="datetime">
<input type="datetime-local">
<input type="email">
<input type="file">
<input type="hidden">
<input type="image">
<input type="month">
<input type="number">
<input type="password">
<input type="radio">
<input type="range">
<input type="reset">
<input type="search">
<input type="submit">
<input type="tel">
<input type="text">
<input type="time">
<input type="url">
<input type="week">