var a = ['Abr','Bfd','Cda'];
var res = ['var аbr = field("ABR")','var bfd = field("Bfd")','var cda = field("Cda")']
var a = ['Abr','Bfd','Cda'];
var map1 = а.map((x) => 'var '+x + ' = ' + 'field("' +x +'");' + '\n' )
// удаления запятых
var rd = map1.join('');
console .log(rd)