What is the representation of π in C++?

There is no native constant representing π in C. You can use the following methods to solve it: use the M_PI constant of the cmath header file; directly assign an approximate value of π; define a macro for π.

How π is represented in C

There is no constant that natively represents π in C. However, the following methods can be used to represent π:

1. Use the math library

C standard librarycmath The header file providesM_PI Constant, its value is π:

<code class="cpp">#include <cmath>

double pi = M_PI;</code>

2. Direct assignment

You can also directly assign the approximate value of π (such as 3.14159265) to a variable ：

<code class="cpp">double pi = 3.14159265;</code>

3. Use macros

In C, you can define macros to represent π:

<code class="cpp">#define PI 3.14159265</code>

Accuracy considerations

Use the M_PI constant to obtain the highest accuracy, while the accuracy of other methods depends on the approximation used. If you need higher precision, you can use the std::acos(-1) function, which returns the value of π:

<code class="cpp">double pi = std::acos(-1);</code>

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