How to convert string to timestamp in PHP

PHP is a widely used programming language that is often used to handle date and time conversion. One common operation is to convert a string into a timestamp for time calculations or comparisons. In this article, we will discuss how to convert string to timestamp in PHP.

1. Using the strtotime() function

PHP provides a function called strtotime(), which can convert a string into a timestamp. This function receives a string representing a time or date as a parameter and returns an integer representing the timestamp.

For example, we convert the string "2021-03-22 15:30:00" into a timestamp in the following code example:

$timestamp = strtotime("2021-03-22 15:30:00");
echo $timestamp;

The function will return a representation of "2021 -03-22 15:30:00" timestamp, we can use this timestamp for further calculations or comparisons.

2. Using the DateTime class

PHP also provides a class called DateTime, which can be used to handle various operations on dates and times, including converting strings into timestamp. Use the DateTime class to get more useful features, such as easily converting strings in different formats into timestamps and ensuring time accuracy by setting the time zone.

The following is a sample code that uses the DateTime class to convert the string "2021-03-22 15:30:00" into a timestamp:

$date = new DateTime("2021-03-22 15:30:00");
$timestamp = $date->getTimestamp();
echo $timestamp;

This code will instantiate a DateTime object, And use its getTimestamp() method to get the timestamp of the object. This method returns an integer representing the timestamp.

3. Using the strptime() function

The strptime() function is another PHP function used to convert a string into a timestamp. It takes two parameters: a string representing a time or date, and a format string specifying the format of the date and time in the string.

The following is a sample code that uses the strptime() function to convert the string "2021-03-22 15:30:00" into a timestamp:

$str = "2021-03-22 15:30:00";
$format = "%Y-%m-%d %H:%M:%S";
$time_array = strptime($str, $format);
$timestamp = mktime($time_array['tm_hour'], $time_array['tm_min'], $time_array['tm_sec'], 
          $time_array['tm_mon']+1, $time_array['tm_mday'], $time_array['tm_year']+1900);
echo $timestamp;

This sample code uses strptime() The function parses the string into a time array and then uses the mktime() function to convert the time array into a timestamp. Each element in the time array represents an aspect of time, such as month, day, hour, and so on.

Summary

This article introduces three methods of converting strings into timestamps in PHP: using the strtotime() function, using the DateTime class, and using the strptime() function. These methods can all be used to convert strings in various formats into timestamps, and can be easily combined with PHP's other date and time functions. Developers can choose the method that best suits their application based on their needs.

The above is the detailed content of How to convert string to timestamp in PHP. For more information, please follow other related articles on the PHP Chinese website!