How to round a cell after user input in Google Sheets? - google-apps-script

Question

It should be a very simple function but I can't find anything that functions the way I need.
I want to have a cell where a number can be entered, then after its entered it is replaced by that number rounded to its nearest 0.25
For example:
I enter 5.26 into cell A1, after i press enter the cell now says 5.25
This should only happen with cell A1, so if i enter 5.26 elsewhere it will stay as 5.26
Any help? Thanks in advance and sorry if this a common question.

Answer 1

This can be achieve by using Google Apps Script and onEdit Trigger.
Follow these steps to achieve the desired goal.
In your Google Sheet, go to Tools -> Script editor.
Delete any code in the script editor and paste code provided below.
Click Save.
Go back to your Google Sheet and type numbers in cell A1.
Press enter and wait the value to change.
Code:
function onEdit(e) {
var range = e.range;
var input = e.value;
if(range.getA1Notation() == "A1" && !isNaN(input)){
var number = (Math.round(input * 4) / 4).toFixed(2);
range.setValue(number);
}
}
Demo:
Triggers let Apps Script run a function automatically when a certain
event, like opening a document, occurs. In your case, we need to use
onEdit since it runs automatically when a user changes the value of
any cell in a spreadsheet. Apps Script passes the
triggered function an event object that contains information about the
context in which the event occurred (usually named e).
In the demo above, I created a condition that will check if the edited cell is A1 and if the inputted value is number. If both satisfy the condition, the script will calculate the value and use range.setValue() to change the value of A1.
References:
Class Range
Range.setValue(value)
Simple Triggers
Event Object