const $$ = ( selector, context = document ) => {
  const regex = /^#/g
  const elements = context.querySelectorAll( selector )

  if ( regex.test( selector ) )
    return elements[ 0 ]

  return elements
}

// $$( '.myjQuery' )[ 0 ].innerHTML = $$( 'div' ).length
// // jQuery
// $( '.jQuery' )[ 0 ].innerHTML = $( 'div' ).length

$$( '#myjQuery' ).innerHTML = $$( 'div' ).length
$( '#jQuery' )[ 0 ].innerHTML = $( 'div' ).length