Returns an exponential string-representation of this.
Converts this to a double before computing the string representation.
If fractionDigits is given then it must be an integer satisfying:
0 <= fractionDigits <= 20. In this case the string contains exactly
fractionDigits after the decimal point. Otherwise, without the parameter,
the returned string uses the shortest number of digits that accurately
represent this.
If fractionDigits equals 0 then the decimal point is omitted.
Examples:
1.toStringAsExponential(); // 1e+0
1.toStringAsExponential(3); // 1.000e+0
123456.toStringAsExponential(); // 1.23456e+5
123456.toStringAsExponential(3); // 1.235e+5
123.toStringAsExponential(0); // 1e+2
Source
String toStringAsExponential([int fractionDigits]);