javascript email validation

 #1

var emailValCheck=/^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$/i;

console.log( emailValCheck.test('someemailvalue@example.com') );

#2

var txt = 'somevalue@example.ocm';

if(txt.indexOf('@')>0){

}

#3

let val = 'somevalue@example.ocm';

if(/^[a-z0-9][a-z0-9-_\.]+@([a-z]|[a-z0-9]?[a-z0-9-]+[a-z0-9])\.[a-z0-9]{2,10}(?:\.[a-z]{2,10})?$/.test(val)) {
   console.log('email validated');
}

#4

var txt = 'somevalue@example.ocm';

txt .match( / some_regex /);