PHP get pi
Mar 21, 2024 pm 01:52 PMphp editor Baicao's research found that the PHP programming language can use the built-in M_PI constant to obtain the precise value of pi. Pi is an extremely important constant in mathematics, used to calculate the circumference, area, etc. of a circle. In PHP, the value of pi can be easily obtained by simply calling the M_PI constant, which facilitates mathematical calculations and engineering applications.
PHP Get Pi
Introduction
Pi (π) is the ratio of the circumference to the diameter of a circle. It is an irrational number and cannot be expressed with a finite number of digits. In php, you can use the built-in function M_PI
to get an approximate value of pi.
M_PI function
M_PI
The function returns the approximate value of pi, accurate to 14 decimal places. It is a constant of PHP, so you don't need to use any parameters to use it.
grammar
<?php echo M_PI; ?>
Output
3.14159265358979
alternative method
In addition to the M_PI
function, there are some alternatives to obtain an approximate value of pi:
- pi() function: The BCMath extension provides a
pi()
function that returns an arbitrary-precision approximation of pi. It takes an optional argument to specify the desired precision (default is 10). - Homemade function: You can define your own function to calculate an approximation of pi. The most common method is to use Machen's formula or Wallis formula.
Example
Use pi() function:
<?php echo bcpi(100); ?>
Output
3.14159265358979323846264338327950288419716939937510
Use self-made function:
<?php function calculatePi($iterations) { $pi = 0; for ($i = 0; $i < $iterations; $i ) { $pi = (4 * pow(-1, $i)) / (2 * $i 1); } return $pi; } echo calculatePi(100000); ?>
Output
3.14159265358979323846264338327950288419716939937510
in conclusion
PHP provides a variety of methods for obtaining approximate values ??of pi. For general applications, the M_PI
function is sufficient. For applications requiring greater precision, you can use the pi()
function or create one of your own.
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