在一行中用 JavaScript 中的正则表达式解析 email； 使右不区分大小写但保持左

Question

1. From my code:

    //yagh... apparently there's an off-chance email is case sensitive... console.log('yooooooooo0 ' + name.substr(name.indexOf('@')+1)); //console.log('yooooooooo1 ' + name.substr(name.indexOf('@')+1).toLowercase()); console.log('yooooooooo1 ' + name.substr(name.indexOf('@')+1).toLowerCase()); console.log('yooooooooo2 ' + name.substr(name.indexOf('@'),0)); console.log('yooooooooo3 ' + name.split('@')[0]); console.log('yooooooooo4 ' + /[^@]*/.exec(name)[0]);//hmmm mh console.log('yooooooooo4_2 ' + /[^@]*$/.exec(name)[0]);//hmmm mh //hm yea okay ya console.log(name);//nondestructive and //pff... console.log((/[^@]*/.exec(name)[0])+'@'+(/[^@]*$/.exec(name)[0]).toLowerCase); let tmp = (/[^@]*/.exec(name)[0])+'@'+ (/[^@]*$/.exec(name)[0]).toLowerCase; console.log(tmp); console.log((/[^@]*/.exec(name)[0])+'@'+name.substr(name.indexOf('@')+1).toLowerCase()); var pass = $('#pass1').val(); var crypto = window.crypto || window.msCrypto; if(crypto.subtle) {

2. Say the email that comes with is a@b.C . The point is, I just found that email is only case insensitive right of the @ . In theory, admins can choose to let that slide, but in practice most won't to prevent confusion (is what I read).

   I want:

    console.log((/[^@]*/.exec(name)[0])+'@'+(/[^@]*$/.exec(name)[0]).toLowerCase);

   I have a working bit that is:

    console.log((/[^@]*/.exec(name)[0])+'@'+name.substr(name.indexOf('@')+1).toLowerCase());

   The first one gives me:

    a@function toLowerCase(){ [native code] }

   And the second:

    a@b.c

   Which is fine, but the first one is prettier and less readable, which is great since no one else will be on it, ever.

   Is there some way to make the first one work? (Assigning it to let tmp= gives the same reply when log ( tmp ).

Answer 1

Replace

console.log((/[^@]*/.exec(name)[0])+'@'+(/[^@]*$/.exec(name)[0]).toLowerCase);

by

console.log((/[^@]*/.exec(name)[0])+'@'+(/[^@]*$/.exec(name)[0]).toLowerCase());

You could also do this

const email = 'some.name@some_domain.com'
const [name, domain] = email.split('@')
console.log(`${name}@${domain}`);