rad2deg() converts an angle measured in radians to degrees. This guide explains the function with focused examples and the decisions that matter in real applications.
What Is rad2deg() in PHP?
Converts an angle measured in radians to degrees.
A typical call looks like this:
<?php
rad2deg($num);
The input arguments shown in the call identify the relevant connection, resource, value, path or configuration for the operation. Pay attention to argument order and to the return value demonstrated below.
Example 1: Basic Usage
This first example uses rad2deg() directly to demonstrate its basic purpose.
<?php
echo rad2deg(pi());
Output:
180The returned value illustrates converts an angle measured in radians to degrees. It changes angle units, not the trigonometric function result itself.
Example 2: A Different Input or Option
The next example changes the input or option, showing another supported use of rad2deg().
<?php
echo rad2deg(pi() / 2);
Output:
90The returned value illustrates converts an angle measured in radians to degrees. It changes angle units, not the trigonometric function result itself.
Practical Example: Applying the Function
In application code, rad2deg() belongs in a controlled workflow with input validation, a checked result and cleanup where needed.
<?php
$angle = atan2(1, 1); echo round(rad2deg($angle));
Output:
45The returned value illustrates converts an angle measured in radians to degrees. It changes angle units, not the trigonometric function result itself.
Important Behavior and Edge Cases
- Main behavior: Converts an angle measured in radians to degrees.
- Important limitation: It changes angle units, not the trigonometric function result itself.
- Requirements: This operation is available in standard PHP; validate inputs and handle failures where relevant.
Comparison With Related Functions
| Function or Approach | When to Use It |
|---|---|
rad2deg() | Converts an angle measured in radians to degrees. |
deg2rad | Converts degrees back to radians, the inverse of rad2deg(). |
Common Beginner Mistakes
| Mistake | Correct Approach |
|---|---|
Ignoring the specific limits or preconditions of rad2deg(). | It changes angle units, not the trigonometric function result itself. |
| Assuming every environment produces the same result. | This operation is available in standard PHP; validate inputs and handle failures where relevant. |
Key Takeaways
- Converts an angle measured in radians to degrees.
- It changes angle units, not the trigonometric function result itself.
- This operation is available in standard PHP; validate inputs and handle failures where relevant.
Use rad2deg() when its behavior matches your task, and verify the relevant return value before taking further action. The output depends on the local configuration when it uses resources, files or an interactive terminal.