const arr1 = [ 1 , 2 , 3 ] ; const arr2 = [ 4 , 5 , 6 ] ; arr1 . push ( ... arr2 ) ; console . log ( arr1 ) ; var parts = [ 'shoulders' , 'knees' ] ; var lyrics = [ 'head' , ... parts , 'and' , 'toes' ] ; console . log ( lyrics ) ; function add ( ... nums ) { return nums . reduce ( ( x , y ) => x + y ) ; } const numbers = [ 25 , - 15 ] ; console . log ( add ( 1 , ... numbers , 66 , ... [ - 10 ] ) ) ;