Open In App

PHP pi( ) Function

Improve
Improve
Like Article
Like
Save
Share
Report

While solving mathematical problems we often come across questions which requires the value of π. Manually inserting the value of PI (π) can be time-consuming and erroneous. It is also not considered as a good programming practice. To solve this issue a built-in function of PHP pi() comes to aid.

The pi() function in PHP is used to return the value of π . Also, M_PI is a named constant PHP which gives identical value to that of returned by pi() function. It is slightly faster than the pi() function.

Some other predefined named constants related to π are :

  • M_PI_2 : It describes π/2. Its value is 1.570796.
  • M_PI_4 : It describes π/4. Its value is 0.785398.
  • M_1_PI : It describes 1/π. Its value is 0.318309.
  • M_PI : It describes π. Its value is 3.141592.
  • M_2_PI : It describes 2/π. Its value is 0.636619.
  • M_SQRTPI : It describes sqrt(π). Its value is 1.772453.
  • M_2_SQRTPI : It describes 2/sqrt(π). Its value is 1.128379.

Syntax:

float pi()

Parameters: This function does not accept any parameter.

Return Value: It returns a floating point value which is an approximate value of PI.

Examples:

Input : echo(pi())
Output : 3.1415926535898

Input : echo M_PI
Output : 3.1415926535898

Below programs illustrate the pi() function in PHP:

  1. When pi() function is used:




    <?php
      
    echo(pi());
      
    ?>

    
    

    Output:

    3.1415926535898
  2. When M_PI is used for finding the value of PI:




    <?php
      
    echo M_PI;
      
    ?>

    
    

    Output:

    3.1415926535898

Important Points To Note:

  • The pi() function can be used to return the value of π.
  • M_PI is a named constant which is slightly faster than the pi() function.
  • pi() function returns the value of pi as float.

Reference:
http://php.net/manual/en/function.pi.php


Last Updated : 22 Jun, 2023
Like Article
Save Article
Previous
Next
Share your thoughts in the comments
Similar Reads