Discussion on: Evaluate all values in an array in Javascript

[Kevin Sullivan]

I'd avoid using Array.prototype.every in this way.
It too will exit as soon as an entry returns false.
MDN - array.prototype.every

It's not because of .every that all of the validations run.
It's because the array is created and all of its items are evaluated, before .every executes

You would get the same result with

function saveProfileIfValid() {
  const isValid = {
    firstName: firstNameIsValid('Jerry'), // <- executes before if( ... )
    lastName: lastNameIsValid('Smith'),   // <- executes before if( ... )
    email: emailIsValid('[e-mail]')   // <- executes before if( ... )
  }
// all the validations have already happened
  if(isValid.firstName && isValid.lastName && isValid.email) { 
    saveProfile(); // save only if all validations pass
  }
}

Hope this helps

[Victor Nascimento]

I thought the same! Good catch. All array methods that rely on the iteratee to return a boolean will stop execution as soon as possible.

[Risa Fujii]

I am still relatively new to Javascript so I appreciate this (I guess Stack Overflow doesn't always have the best solution haha). I will update my code. Thank you both!