Check comma separated email address is valid

The following Google Apps Script is designed to loop through a Google Sheet cell of email addresses that have been separated by a comma and space. It then uses a regular expression (regex) to confirm the email address meets the correct formatting criteria.

This code was developed as a way of implementing additional checks when asking users to be precise in how exactly they enter multiple email addresses. So if they were to forget the space for instance it could alert them, before the rest of the code risked failing as whatever task it was designed to do.

Regular expression to check the format of an email address

Regex breakdown

• ^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$
• ^  matches the beginning of the string.
• [a-zA-Z0-9._%+-]  match any character in this set e.g. from "a" to "z" and any "." or "_"
• +  match one or more of the preceding token.
• @  match a "@" character.
• [a-zA-Z0-9.-]  match any character in this set e.g. from "a" to "z" and any "." or "-"
• \.  escaped character to match a "."
• [a-zA-Z]  match any character in this set e.g. from "a" to "z"
• {2,}  match two or more of the preceding token.
• $  matches the end of the string.

Therefore something like "example1@gmail.com" will be accepted but "example2@gmailcom" will not.

Download

Check comma separated email address is valid download (please use 'File' > 'Make a copy' for your own version).

	/**
	* Developed by The Gift of Script: https://www.pbainbridge.co.uk/
	*/
	function checkEmailAddresses() {
	// create regular expression for testing valid email address
	var emailAddressRegEx = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/gm;
	// get Data sheet
	var ss = SpreadsheetApp.getActiveSpreadsheet();
	var dataSheet = ss.getSheetByName("Data");
	// get cell containing email addresses
	var emailAddressCell = dataSheet.getRange(5, 3).getValue();
	console.log(emailAddressCell);
	// split email addresses by comma and space
	var emailAddressArray = emailAddressCell.split(", ");
	// loop through each email address
	var emailAddressArrayLength = emailAddressArray.length;
	for (var i = 0; i < emailAddressArrayLength; i++) {
	// get single email address
	var singleEmailAddress = emailAddressArray[i];
	console.log("singleEmailAddress is: " + singleEmailAddress);
	// test valid email address against RegEx
	var checkEmailAddress = singleEmailAddress.match(emailAddressRegEx);
	if (checkEmailAddress) {
	console.log("This is a valid email address format.");
	} else {
	console.log("This is an invalid email address format.");
	// launch HTML popup
	var popupTitle = "Invalid email address format";
	var popupMessage = "There is a problem with the following email address, please ensure you have entered it correctly into the Google Sheet with a comma and space.<br/><br/>Email address: " + singleEmailAddress;
	var htmlOutput = HtmlService
	.createHtmlOutput(popupMessage)
	.setWidth(380)
	.setHeight(180);
	SpreadsheetApp.getUi().showModalDialog(htmlOutput, popupTitle);
	// break out of the loop to stop
	break;
	};
	};
	}

view raw Check comma separated email address is valid.gs hosted with ❤ by GitHub