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PHP hrtime() Function: Usage and Examples

Learn how to uses hrtime to process its supported input in PHP with syntax, practical examples, edge cases, and common mistakes.

1 views Published Oct 16, 2026 Updated Oct 16, 2026

When a PHP application needs to uses hrtime to process its supported input, choosing the right API and checking its results helps keep code understandable and dependable. This guide explains hrtime with focused examples and important details.

What Is hrtime in PHP?

hrtime uses hrtime to process its supported input. Monotonic time is suited to intervals, not wall-clock timestamps.

Syntax:

hrtime(as_number) : array|int|float|false

Parameters and return value: Parameters: <optional> bool $as_number = false. Check the return value or modified object rather than assuming the operation always succeeds.

Important: The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.

Example 1: Basic Usage

Start with a compact input so the main operation is visible.

<?php

echo hrtime(true);

Uses hrtime to process its supported input. Monotonic time is suited to intervals, not wall-clock timestamps.

Example 2: A Different Input

The next example changes the input or option to illustrate another behavior.

<?php

print_r(hrtime());

Compare this result with the first example. Monotonic time is suited to intervals, not wall-clock timestamps.

Practical Example: Applying the Function

This example combines the API with a realistic processing step and shows where to check its result.

<?php

$start = hrtime(true);
for ($index=0;$index<10000;$index++) { sqrt($index); }
$elapsedMilliseconds = (hrtime(true)-$start)/1e6;
printf("%.3f ms",$elapsedMilliseconds);

Adapt the inputs to your application and validate the output before storing or displaying it. Monotonic time is suited to intervals, not wall-clock timestamps.

Important Behavior and Edge Cases

  • Main purpose: Uses hrtime to process its supported input.
  • Errors and boundaries: Monotonic time is suited to intervals, not wall-clock timestamps.
  • Environment: The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.

Comparison With Related Functions

Function or ApproachWhen to Use It
hrtimeUses hrtime to process its supported input.
Related PHP functionsConsider this alternative when you need different behavior or a different abstraction.

Common Beginner Mistakes

MistakeCorrect Approach
Assuming the operation succeeds for every inputMonotonic time is suited to intervals, not wall-clock timestamps.
Ignoring runtime requirements or variable outputThe code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.
Using the wrong API for the goalCompare hrtime with Related PHP functions before selecting an approach.

Key Takeaways

  • Uses hrtime to process its supported input.
  • Monotonic time is suited to intervals, not wall-clock timestamps.
  • The code examples use representative input rather than production credentials. Confirm that the required PHP extension is installed.

Use hrtime when you need to uses hrtime to process its supported input. The three examples move from a simple call to a practical use. Validate all external input and handle failures explicitly.

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