输入类型“ number”不会调整大小

Seem like the input type number does not support size attribute or it's not compatible along browsers, you can set it through CSS instead:

input[type='number']{
width: 80px;
}

Updated Fiddle

Incorrect usage.

Input type number it's made to have selectable value via arrows up and down.

So basically you are looking for "width" CSS style.

Input text historically is formatted with monospaced font, so size it's also the width it takes.

Input number it's new and "size" property has no sense at all*. A typical usage:

<input type="number" name="quantity" min="1" max="5">

w3c docs

to fix, add a style:

<input type="number" name="email" style="width: 7em">

EDIT: if you want a range, you have to set type="range" and not ="number"

EDIT2: *size is not an allowed value (so, no sense). Check out official W3C specifications

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

Tip: To specify the maximum number of characters allowed in the element, use the maxlength attribute.

For <input type=number>, by the HTML5 CR, the size attribute is not allowed. However, in Obsolete features it says: “Authors should not, but may despite requirements to the contrary elsewhere in this specification, specify the maxlength and size attributes on input elements whose type attributes are in the Number state. One valid reason for using these attributes regardless is to help legacy user agents that do not support input elements with type="number" to still render the text field with a useful width.”

Thus, the size attribute can be used, but it only affects older browsers that do not support type=number, so that the element falls back to a simple text control, <input type=text>.

The rationale behind this is that the browser is expected to provide a user interface that takes the other attributes into account, for good usability. As the implementations may vary, any size imposed by an author might mess things up. (This also applies to setting the width of the control in CSS.)

The conclusion is that you should use <input type=number> in a more or less fluid setup that does not make any assumptions about the dimensions of the element.

Rather than set the length, set the max and min values for the number input.

The input box then resizes to fit the longest valid value.

If you want to allow a 3-digit number then set 999 as the max

 <input type="number" name="quantity" min="0" max="999">

Use an on onkeypress event. Example for a zip code box. It allows a maximum of 5 characters, and checks to make sure input is only numbers.

Nothing beats a server side validation of course, but this is a nifty way to go.

function validInput(e) {
e = (e) ? e : window.event;
a = document.getElementById('zip-code');
cPress = (e.which) ? e.which : e.keyCode;


if (cPress > 31 && (cPress < 48 || cPress > 57)) {
return false;
} else if (a.value.length >= 5) {
return false;
}


return true;
}

#zip-code {
overflow: hidden;
width: 60px;
}

<label for="zip-code">Zip Code:</label>
<input type="number" id="zip-code" name="zip-code" onkeypress="return validInput(event);" required="required">

change type="number" to type="tel"

What you want is maxlength.

Valid for text, search, url, tel, email, and password, it defines the maximum number of characters (as UTF-16 code units) the user can enter into the field. This must be an integer value 0 or higher. If no maxlength is specified, or an invalid value is specified, the field has no maximum length. This value must also be greater than or equal to the value of minlength.

You might consider using one of these input types.

Use min and max value instead of using size for "number" type, Input box size will be auto adjusted according to max value.

number: