var formatThousands = require('format-thousands');

formatThousands(1000);
//=> '1 000'

formatThousands(5000, {formatFourDigits: false});
//=> '5000'

formatThousands(1000000, '`');
//=> '1`000`000'

formatThousands(10000, {separator: "'"});
//=> "10'000"

formatThousands(-100000);
//=> "-100 000"

formatThousands(10000.0001)
//=> "10 000.0001"

formatThousands();
//=> ''