How I can skip the element of array .map?

Question

var userids = userbody.contacts.map(function(obj){

  if((obj.iAccepted=='true')&&(obj.contactAccepted=='true')) {
    console.log(true);
    return obj.userID //return obj.userID
  } 

});

This will give the result like this:

[ '0', '35', '37', '30', '34', '36', '33', '32', undefined, '332', '328', '337', '333', undefined ]

I want to skip the undefined elements in the array.

Answer 1

This is what Array.prototype.filter() is for. You need to do this in two steps.

var userids = userbody.contacts
    .filter(contact => contact.iAccepted == 'true' && contact.contactAccepted == 'true')
    .map(contact => contact.userId);

The filter part takes out all unnecessary elements, then map converts the rest to the way you want.