The modular division operator '%' can be used to get the remainder of a division in JS. This means that if we perform the modular division of a floating point number by 1, we get the value after the decimal point. Further, if we build a loop where we multiply by 10 until there is no longer anything after the decimal point, we can find the smallest power of ten we can multiply the original number by to get an integer.
Example below:
function getE(floatingPointValue)
{
var x = floatingPointValue;
var digitsAfterDecimal = 0;
while(x % 1 != 0)
{
x = x * 10;
digitsAfterDecimal++;
}
return x.toString() + " *10^-" + digitsAfterDecimal;
}
Fiddle: http://jsfiddle.net/L8XtP/2/
Hope this helps!