laravel - Select Box Blade -

i try remove ids select box display name , surname , licence number licence object

here controller :

 $licence_entraineur = licencies::select('lb_nom', 'num_licence', 'lb_prenom', 'id')             ->where(['structure_id' => auth::user()->structure->id])             ->where('type_licence_id' , '1')             ->get()             ->map(function($i) {                 return [$i->lb_nom.' - '.$i->lb_prenom.' - n°'.$i->num_licence];             }); 

here blade view :

 {!! form::select('licence_entraineur_id', $licence_entraineur ,  null, ['class' => 'form-control select2', 'placeholder' => 'selectionnez un entraineur']) !!} 

everything works when go view , make dropdown of select box , values display :

0 mourareau - mathieu - 17085696

1 antoine - george - 17209669

2 aurore - alonso - 17856965

i remove 0 , 1 , 2 , ... numbers view

someone know how achieve ? lot in advance

in laravel 5.4 can use mapwithkeys(). i've tested , works in 5.4 (in 5.3 helper has bug, it's not working):

$licence_entraineur = licencies::select('lb_nom', 'num_licence', 'lb_prenom', 'id')         ->where(['structure_id' => auth::user()->structure->id])         ->where('type_licence_id' , '1')         ->get()         ->mapwithkeys(function($i) {             return [$i->id => $i->lb_nom.' - '.$i->lb_prenom.' - n°'.$i->num_licence];         });