how to calculate mathematical double values

I need to calculate 4.0468564224e-33 value. But unfortunately 开发者_运维问答I am getting a result of 0.0000000. I think the problem is at the e value.

How can I calculate these mathematical calculation? Is there any necessity of importing mathematical classes?

---

4.0468564224e-33 is 4.0468564224 * 10⁻³³, that is 0.0000000000000000000000000000000040468564224 - very close to zero.

If your output function is rounding to 7 decimal digits, you would get 0.0000000 as output even though the input is correct.

---

Anders Lindahl explained why you see zero, but didn't suggest any solution.

One solution is to request the output of more decimals by using %.43f instead of %f (%.7f).

Another solution is to request exponentiation notation by using %e (%.10e) instead of %f.

---

Probably you are using something like

NSLog("%d", yourValue);

while you should use:

NSLog("%f", yourValue);

since your value is a float and not an integer.

%d => int
%f => float

---

Try using NSNumber for your large double calculation. Read Apple Doc for NSNumber

See SO post for NSNumber

NSNumber Calculations & precision?