About double

Language Help Java
1

Hi, I am learning computer science ap class ( java) I am reading the page that teach double:
https://www.codecademy.com/paths/ap-computer-science-a/tracks/apcs-writing-your-first-java-program/modules/apcs-variables/lessons/learn-java-variables/exercises/doubles

I don’t understand the E+308 in the following paragraph


The `double` primitive data type can help. `double` can hold decimals as well as very large and very small numbers. The maximum value is 1.797,693,134,862,315,7 E+308, which is approximately 17 followed by 307 zeros. The minimum value is 4.9 E-324, which is 324 decimal places!

I searched online and find E308 is 308 zero after the number, but I don’t know what does E+308 mean

2

It’s one of the standard notations for displaying very large and very small numbers and refers to an Exponent of ten.

For example E+308 means that the overall number is being multiplied by 10 to the power of 308 and E-324 means the number is multiplied by 10 to the power of -324.

1.797,693,134,862,315,7 E+308
and
4.9 E-324

is just another way of writing:

1.797,693,134,862,315,7 * 10^308 (A huge number)
and
4.9 * 10^-324 (An infinitesimally small number)
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3

To add onto Lyall’s answer (and to provide a numeric representation with small numbers):

1.9 E+2
= 1.9 * 10^2
= 1.9 * 100
= 190

Or

1.9 E-2
= 1.9 * 10^(-2)
= 1.9 * 0.01
= 0.019
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