Editing Data cleaning (section)

=== Verify the strings are in valid email format ===
Rule: Email contains @ symbol

* EXCEL: {{kbd | key =<nowiki>=IF(ISERR(FIND("@", A2, 1)), FALSE, TRUE)</nowiki>}} only check the field if contains @ symbol or not
** result: (1) normal condition: return TRUE; (2) exceptional condition: return '''FALSE''' if @ symbol was not found 
* EXCEL: {{kbd | key =<nowiki>=FIND("@", A2, 2)</nowiki>}} only check the field if contains @ symbol or not
** syntax: <nowiki>FIND(find_text, with_text, [start_num])</nowiki> the start_num is 2 because the position of  @ symbol should be larger than 1 (position of first char is 1)
** result: (1) normal condition: return the number larger than 1; (2) exceptional condition: return '''#VALUE!''' if @ symbol was not found 
* PHP: [http://www.w3schools.com/php/filter_validate_email.asp PHP FILTER_VALIDATE_EMAIL Filter]
** "Returns the filtered data, or '''FALSE''' if the filter fails." quoted from [http://php.net/manual/en/function.filter-var.php PHP.net]