The number to format.
OptionalminimumFractionDigits: numberThe minimum number of fraction digits to display.
OptionalmaximumFractionDigits: numberThe maximum number of fraction digits to display.
formatNumber(1234.5678) returns "1,234.57" (default 2 fraction digits).formatNumber(1234.5, 1, 3) returns "1,234.5" (minimum 1, maximum 3 fraction digits).
Formats a number with specified fraction digits.