如何转换或舍入像`-7.5E + 37`这样的数字

Question

It might include a general math question.

I am using Math calculation library trader

trader_stddev function returns like -7.5E+37

I need to round this for mor simple percentage.

round($number,2)

doesn't work.

How can I make it ? and How do you call this E ??( I would like to google around about this E but I am not sure how to call this)

Answer 1

This is scientific notation. The e stands for exponent or the exponential function, and this is how PHP reports extremely large (or extremely small) numbers. So your number is actually -7.5 x (10^37).

Instead of round(), you can use number_format() to get what you need:

number_format($number, 2);