How to convert timestamp to millisecond timestamp in PHP

PHP is a very popular programming language used to create powerful applications in web development. In PHP, timestamp is a very important concept, representing the number of seconds since 0:00:00 on January 1, 1970. However, in some cases we need to convert the timestamp to millisecond timestamp. This article will show you how to convert timestamp to millisecond timestamp in PHP.

1. Understanding timestamps and millisecond timestamps

In PHP, the timestamp is an integer that represents the current time and the Unix epoch (i.e. January 1, 1970 0:00:0 The number of seconds between UTC). For example, the timestamp of the current time is:

echo time(); // 1622881674

A millisecond timestamp is an extension of Unix time that represents the number of milliseconds since Unix. For example, if you have a timestamp with timestamp 1622881674 and you want to convert it to a millisecond timestamp, you can multiply by 1000:

$milliseconds = time() * 1000; // 1622881674000

2. Use the microtime function to get the millisecond timestamp

microtime() function is used in PHP to return the number of microseconds of the current time (that is, one millionth of a second). Using this function, we can get the millisecond timestamp of the current time.

list($msec, $sec) = explode(' ', microtime());
$milliseconds = floor($sec * 1000 + $msec * 1000);
echo $milliseconds; // 1622881674000

The above code first uses the explode() function to divide the string returned by microtime() into two parts: seconds and microseconds. The code then converts the seconds to milliseconds and adds the microseconds to get a millisecond timestamp for the current time.

3. Use DateTime object to obtain millisecond timestamp

The DateTime class is one of the commonly used classes for processing date and time in PHP. It provides many useful methods to manipulate time. Using the DateTime object, we can convert the timestamp into a millisecond timestamp.

$datetime = new DateTime();
$milliseconds = $datetime->format('u') / 1000 + $datetime->getTimestamp() * 1000;
echo $milliseconds; // 1622881674000

The above code uses a DateTime object to get the current date and time and formats it as "u" (for microseconds). The code then divides the microseconds by 1000 to get the milliseconds and multiplies the timestamp by 1000 to get the millisecond timestamp for the current time.

Conclusion

Converting timestamp to millisecond timestamp in PHP is very simple. You can do this using the time() function and multiplication operator, the microtime() function, or the DateTime class. All the above methods can help you handle millisecond-level timestamps in web development to meet your needs.

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