What are the functions changed in PHP 6?

With the development of technology, PHP 6 has also brought some new changes and changes. Among them, one of the most significant changes is the change of some important functions in PHP 6. This article will introduce some important function changes.

1. Changes in strlen function

In PHP 5, we often use the strlen function to get the length of a string. In PHP 6, this function has been refactored. In PHP 6, the strlen function will count the number of Unicode characters, not the number of bytes. This means that if we use Unicode characters in a string, the length of the string will be different than what we expect.

For example, when we use the strlen function to calculate the length of the string "Hello, world!", the returned result will be 8 instead of 6 because it contains two Unicode characters.

2. Changes in json_decode function

When processing json data, we usually use the json_decode function to convert the json data into a php array so that we can process it in php. In PHP 6, the default behavior of this function has changed somewhat.

In php 6, when we try to use the json_decode function to convert a json string into a php array, if the json string contains a reference to a php variable (using the "&" symbol), then The json_decode function will throw an exception.

3. Changes in the explode function

In PHP 5, we use the explode function to split a string into an array according to the specified delimiter. In PHP 6, the behavior of this function has also undergone some changes.

In PHP 6, the explode function will no longer support using the empty string as the delimiter to split a string. If we still use the empty string as the delimiter, the explode function will throw an exception. However, we can still use spaces as delimiters to split a string.

4. Mysql_connect function changes

In PHP 5, we use the mysql_connect function to connect to the mysql database. In PHP 6, this function has been deprecated and is no longer available.

On the contrary, in PHP 6 it is recommended that we use the mysqli_connect function to connect to the mysql database. The mysqli_connect function provides better performance and more features. Moreover, the mysqli_connect function also supports preprocessing mode, which can effectively avoid SQL injection attacks.

Summary

The above introduces some important function changes in PHP 6. These changes have a certain impact on our PHP development work. Therefore, we need to understand these changes and pay more attention in subsequent development work in order to better use PHP 6 to develop high-quality applications.

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