The microtime() function is an inbuilt function in PHP which is used to return the current Unix timestamp with microseconds. The $get_as_float is sent as a parameter to the microtime() function and it returns the string microsec sec by default.
microtime( $get_as_float )
Parameters: This function accepts single parameter $get_as_float which is optional. If $get_as_float is set to TRUE then it specify that the function should return a float, instead of a string.
Return Value: It returns the string microsec sec by default, where sec is the number of seconds since the Unix Epoch (0:00:00 January 1, 1970, GMT), and microsec is the microseconds part. If the $get_as_float parameter is set to TRUE, it returns a float representing the current time in seconds since the Unix epoch accurate to the nearest microsecond.
Exceptions: The microtime() function is only available on operating systems that support the gettimeofday() system call.
Below programs illustrate the microtime() function in PHP:
The micro time is :0.51423700 1535452933
The micro time is :1535452935.2589