PHP phpversion() Function: Usage and Examples

Reports the current PHP version or the version of a named loaded extension.

What It Does and When to Use It

Read the current runtime version string. A minimum platform requirement controls what syntax can be parsed; target-version tests find runtime and extension incompatibilities.

Requirements, Inputs and Expected Behavior

Confirm the runtime, extension, environment variables, and permissions before running the examples in production. An extension can be loaded but not report a version; false must be handled.

Example 1: Basic Operation

Read the current runtime version string.

<?php
echo phpversion(), "
";

Example 2: Behavior and Validation

Ask for an extension-specific version and handle false.

<?php
$version = phpversion('Zend OPcache');
 echo $version === false ? 'No extension version found' : $version;

Practical Example: Application Use

Gate a feature by comparing PHP versions numerically.

<?php
if (version_compare(phpversion(), '8.4.0', '<')) {
     throw new RuntimeException('PHP 8.4 or later is required');
 }
 echo 'Compatible runtime';

Important Behavior and Edge Cases

The second example highlights: Ask for an extension-specific version and handle false. The practical example adds: Gate a feature by comparing PHP versions numerically.

Comparison with Related Approaches

Common Beginner Mistakes

Key Takeaways

• Reports the current PHP version or the version of a named loaded extension.
• Gate a feature by comparing PHP versions numerically.
• Do not introduce syntax from a newer minor version before every production host supports it.