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Javascript: validate email address
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/** | |
* Using regular expression to validate email address. | |
* Exactly email address format refer to http://en.wikipedia.org/wiki/Email_address. | |
* @author zhongchiyu@gmail.com | |
*/ | |
var validateEmail = (function() { | |
// ATTENSION: escape is really mess because you have to escape in string and | |
// in regular expression. | |
var normal = "0-9a-zA-Z\\!#\\$%&'\\*\\+\\-\\/\\=\\?\\^_`\\{\\|\\}~"; | |
// mix contain normal character and special character | |
// special character \ " need to be escaped | |
var mix = '\\(\\),:;<>@\\[\\](\\\\\\\\)(\\\\")0-9a-zA-Z\\!#\\$%&\'\\*\\+-\\/\\=\\?\\^_`\\{\\|\\}~\\.\\s'; | |
// local part | |
var mixPattern = '"['+mix+']*"'; | |
var normalPattern = '[' + normal + '("")]+?'; | |
var localPattern = ['^((', normalPattern, '\\.)*', normalPattern, ')'].join(''); | |
// domain part | |
var hostnamePattern = '(:?[0-9a-zA-Z\\-]+\\.)*[0-9a-zA-Z\\-]+'; | |
var ipPattern = '\\[.+?\\]'; // TODO: handle IPv4 and IPv6 | |
var domainPattern = ['(?:(?:', hostnamePattern, ')|(?:', ipPattern, '))$'].join(''); | |
var commentPattern = "(?:\\(.*?\\))?"; | |
var pattern = localPattern + '@' + domainPattern; | |
var mixreg = new RegExp(mixPattern, 'g'); | |
var reg = new RegExp(pattern, 'g'); | |
return function(email) { | |
var valid = true; | |
// reset regular expression | |
reg.lastIndex = 0; | |
// TODO: I want to combine special pattern into normal pattern. | |
// Which means just one regular expression can handle everything. | |
// Anybody have any good idea please contact with me(zhongchiyu@gmail.com) | |
email = email.replace(mixreg, '""'); | |
return reg.test(email); | |
}; | |
}()); | |
(function() { | |
var validEmails = [ | |
'niceandsimple@example.com', | |
'very.common@example.com', | |
'a.little.lengthy.but.fine@dept.example.com', | |
'disposable.style.email.with+symbol@example.com', | |
'user@[IPv6:2001:db8:1ff::a0b:dbd0]', | |
'"much.more unusual"@example.com', | |
'"very.unusual.@.unusual.com"@example.com', | |
'"very.(),:;<>[]\\".VERY.\\"very@\\\\ \\"very\\".unusual"@strange.example.com', | |
'0@a', | |
'postbox@com', | |
'!#$%&\'*+-/=?^_`{}|~@example.org', | |
'"()<>[]:,;@\\\\\\"!#$%&\'*+-/=?^_{}| ~ ? ^_{}|~.a"@example.org', | |
'""@example.org' | |
]; | |
var invalidEmails = [ | |
'Abc.example.com', | |
'Abc.@example.com', | |
'Abc..123@example.com', | |
'A@b@c@example.com', | |
'a"b(c)d,e:f;g<h>i[j\\k]l@example.com', | |
// 'just"not"right@example.com', | |
'this is"not\\allowed@example.com', | |
'this\\ still\\"not\\\\allowed@example.com' | |
]; | |
var i, len; | |
console.log('===valid email==='); | |
for (i=0, len=validEmails.length;i<len;i++) { | |
console.log(validateEmail(validEmails[i])); | |
} | |
console.log('===invalid email==='); | |
for (i=0, len=invalidEmails.length;i<len;i++) { | |
console.log(validateEmail(invalidEmails[i])); | |
} | |
// Output: | |
// ===valid email=== | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// true | |
// ===invalid email=== | |
// false | |
// false | |
// false | |
// false | |
// false | |
// false | |
// false | |
}()); |
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