A brief discussion on how PHP handles millisecond-level timestamps

Under normal circumstances, when we use timestamps, we often use second-level timestamps. But during the programming process, sometimes we need to use millisecond-level timestamps. As a powerful programming language, PHP also provides us with a rich function library for timestamp processing. Today we will talk about the relevant knowledge of PHP millisecond timestamp conversion.

1. What is a timestamp

In computer science, a timestamp is a value composed of a set of numbers, which represents a certain point in time, usually Refers to the number of seconds that have elapsed from the Unix epoch (i.e. 00:00:00 UTC on January 1, 1970) to the current time. Timestamp is one of the commonly used time representation methods in computer programs, especially in time comparison and calculation operations. It is widely used.

2. The difference between millisecond timestamp and second timestamp

The core difference between millisecond timestamp and second timestamp is the accuracy of time. The precision of second timestamps is at the second level, while the precision of millisecond timestamps is at the millisecond level. In layman's terms, it means adding a three-digit decimal precision representation to the second timestamp.

In PHP, we can get the second-level timestamp of the current time through the time() function. For example:

$timestamp = time(); //获取当前时间戳

When converting millisecond-level timestamps, we need to use the timestamp processing function in PHP.

3. PHP millisecond timestamp conversion function

In PHP, we have the following three commonly used millisecond timestamp conversion functions:

1. microtime()

The microtime() function is used to obtain the millisecond timestamp of the current time. It returns a string containing the current timestamp and microseconds. The syntax of the function is as follows:

microtime([bool $get_as_float])

The parameter $get_as_float indicates whether to convert the return value to a floating point number. If set to true, returns a floating point number.

Usage example:

$microtime = microtime(); //获取当前时间戳及微秒数
echo $microtime; //输出 0.123456 1462312701

2. DateTime object

DateTime object can be used to process time information in various time formats and time zones. By setting the formatting method, we can easily convert second-level timestamps to millisecond-level timestamps.

Usage example:

$timestamp = time(); //获取当前时间戳
$date_time = new DateTime("@$timestamp"); //@符号表示使用Unix时间戳格式
$millisecond_timestamp = $date_time->format('u'); //输出当前时间毫秒级别时间戳

3. date() function

date() function is one of the time and date functions in PHP and can be used for formatting output time information. When using the date() function, we need to multiply the second-level timestamp by 1000 before performing date formatting.

Usage example:

$timestamp = time(); //获取当前时间戳
$millisecond_timestamp = $timestamp * 1000; //将秒级别时间戳转换为毫秒级别时间戳
$date_time = date('Y-m-d H:i:s.u', $millisecond_timestamp / 1000); //输出当前时间毫秒级别时间戳

4. Summary

Today we introduced how to process millisecond-level timestamps in PHP and explained three types Commonly used millisecond timestamp conversion functions include microtime() function, DateTime object and date() function. In addition, we can also process and convert timestamps through other methods. No matter which method we use, sophisticated timestamp processing techniques can bring us a more efficient programming experience.

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