Analysis of Two float (floating point number) comparison instances in PHP

This article mainly introduces two float (floating point number) comparisons in PHP, and analyzes the use skills of the bccomp function for floating point number comparison in the form of a complete example, which has some reference value, for more information about how to compare two float (floating point number) methods in PHP, see the following example. Share it with you for your reference. The details are as follows:

Recently, when I was developing a contract management system, two floating point numbers were involved, which made me miserable.
A long time ago, N did not know where to hear a "truth" that "do not use equal signs to compare floating-point numbers". he was using it at ordinary times. It seemed that there was no problem, but this problem finally came.

<? Php $ sum = "12300.00"; $ a = "10000.30"; $ B = "2000.30"; $ c = "299.40"; $ sum = (float) $ sum; $ s = (float) ($ a + $ B + $ c); var_dump ($ sum, $ s); var_dump ($ sum = $ s );

The result is:

Float (12300)
Float (12300)
Bool (false)

Later I learned that in PHP, to compare the two floating point numbers, we can use bccomp (parameter 1, parameter 2, decimal place) to compare them.

<? Php $ sum = "12300.00"; $ a = "10000.30"; $ B = "2000.30"; $ c = "299.40"; $ sum = (float) $ sum; $ s = (float) ($ a + $ B + $ c); var_dump ($ sum, $ s); var_dump (bccomp ($ sum, $ s, 2 ));

Result:

Float (12300)
Float (12300)
Int (0) // 0 indicates that two floating point values are equal

For details about how to use the bccomp function, refer to the PHP Manual.

I hope this article will help you with php programming.