HTMLInputElement: stepUp() method
The HTMLInputElement.stepUp()
method increments the value
of a numeric type of <input>
element by the value of the
step
attribute, or the
default step
value if the step attribute is not explicitly set. The method,
when invoked, increments the value
by
(step
* n), where n
defaults to
1
if not specified, and
step
defaults to the
default value for step
if not specified.
Input type | Default step value | Example step declaration |
---|---|---|
date | 1 (day) |
7 day (one week) increments:<input type="date" min="2019-12-25" step="7"> |
month | 1 (month) |
12 month (one year) increments:<input type="month" min="2019-12" step="12"> |
week | 1 (week) |
Two week increments:<input type="week" min="2019-W23" step="2"> |
time | 60 (seconds) |
900 second (15 minute) increments:<input type="time" min="09:00" step="900"> |
datetime-local | 1 (day) |
Same day of the week:<input type="datetime-local" min="019-12-25T19:30"
step="7"> |
number | 1 |
0.1 increments<input type="number" min="0" step="0.1" max="10"> |
range | 1 |
Increments by 2:<input type="range" min="0" step="2" max="10"> |
The method, when invoked, changes the form control's value by the value given in the
step
attribute, multiplied by the parameter, within the constraints set on
the form control. The default value for the parameter, if no value is passed, is
1
. The method will not cause the value to exceed the
set max
value, or defy
the constraints set by the
step
attribute.
If the value before invoking the stepUp()
method is invalid—for example,
if it doesn't match the constraints set by the step attribute—invoking the
stepUp()
method will return a value that does match the form controls
constraints.
If the form control is non time, date, or numeric in nature, and therefore does not
support the step
attribute (see the list of supported input types in the
table above), or if the step value is set to any
, an
InvalidStateError
exception is thrown.
Syntax
js
stepUp()
stepUp(stepIncrement)
Parameters
stepIncrement
Optional-
A numeric value. If no parameter is passed,
stepIncrement
defaults to1
.
Return value
None (undefined
).
Examples
Click the button in this example to increment the number input type:
HTML
html
<p>
<label for="theNumber">
Enter a number between 0 and 400 that is divisible by 5:
</label>
<input type="number" step="5" id="theNumber" min="0" max="400" />
</p>
<p>
<label>
Enter how many values of step you would like to increment by or leave it
blank:
</label>
<input type="number" step="1" id="incrementInput" min="0" max="25" />
</p>
<input type="button" value="Increment" id="theButton" />
JavaScript
js
/* make the button call the function */
const button = document.getElementById("theButton");
button.addEventListener("click", () => {
stepOnUp();
});
function stepOnUp() {
let input = document.getElementById("theNumber");
let val = document.getElementById("incrementInput").value;
if (val) {
/* increment with a parameter */
input.stepUp(val);
} else {
/* or without a parameter. Try it with 0 */
input.stepUp();
}
}
CSS
css
input:invalid {
border: red solid 3px;
}
Result
Note if you don't pass a parameter to the stepUp
method, it defaults to
1
. Any other value is a multiplier of the step
attribute
value, which in this case is 5
. If you pass 4
as the
stepIncrement
, the input will stepUp
by
4 * 5
, or 20
. If the parameter is 0
, the number
will not be incremented. The stepUp will not allow the input to out of range, in this
case stopping when it reaches 400
, and rounding down any floats that are
passed as a parameter.
Try setting the step increment input to 1.2
. What happens when you invoke the
method?
Try setting the value to 4
, which is not valid. What happens when you
invoke the method?
Specifications
Specification |
---|
HTML Standard # dom-input-stepup-dev |
Browser compatibility
BCD tables only load in the browser
See also
<input>
HTMLInputElement
HTMLInputElement.stepDown
-
step
,min
andmax
attributes