PHP microtime() Function
Quick summary: The PHP microtime() function returns the current Unix timestamp with microseconds.
PHP microtime() Syntax
microtime(bool $as_float = false): string|floatPHP
PHP microtime() Basic examples
var_dump(microtime(true));PHP
Output:
float(1707398400.1234)Returns high-precision timestamps.
PHP microtime() Real-world usage
$start = microtime(true);
usleep(500000);
echo microtime(true) - $start;PHP
Output:
0.5Measures execution time accurately.
PHP microtime() Edge cases
var_dump(microtime());PHP
Output:
string(...) "0.12345600 1707398400"Returns a string when called without arguments.
PHP microtime() Common mistakes
Forgetting the true parameter
Without true, microtime returns a string.
Incorrect
microtime();Correct
microtime(true);Pass true to get a float.
PHP microtime() Frequently Asked Questions
What does microtime() do?
Returns current Unix timestamp with microseconds.
Use case?
Measuring execution time.
Return format?
String or float.
Difference from time()?
Higher precision.
Performance?
Fast.
Common mistake?
Using string format incorrectly.
Can return float?
Yes with true flag.
Used in profiling?
Yes.
Safe?
Yes.
Precision level?
Microseconds.
Alternative?
hrtime().
Best practice?
Use float mode.