Why does +e canceled and -e not?

Question

System.out.println(2e+5);

Above line's output is,

200000.0

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While below line's,

System.out.println(2e-5);

output is,

2.0e-5

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Why does 2e-5 is not solved down with -10^5 giving the output,

0.00002

Answer 1

Because that's how the designers of the Double class chose to implement it:

[...]

• If m is greater than or equal to 10^-3 but less than 10⁷, then it is represented as the integer part of m, in decimal form with no leading zeroes, followed by '.' ('\u002E'), followed by one or more decimal digits representing the fractional part of m.
• If m is less than 10^-3 or greater than or equal to 10⁷, then it is represented in so-called "computerized scientific notation." [...]

They could have made another choice, of course, but that's simply how it is.

As the documentation says, if you want a specific format, use a NumberFormat to format your double.