PHP built-in functions, essential tools

As a popular programming language, PHP’s widespread use benefits from its flexibility and powerful built-in functions. These built-in functions can both speed up the development process and improve code readability and maintainability. Whether you are a beginner or an experienced developer, you should know and master these essential tools.

Some commonly used PHP built-in functions include:

String functions

In PHP, strings are one of the most common data types. String functions allow us to process strings, such as search, replace, split, and format. Commonly used string functions include:

• strlen(): Returns the length of a string.
• strpos(): Find the position of a specific character or substring in a string.
• substr(): Intercept a substring from a string.
• str_replace(): Replace a substring in a string with another string.

Array function

Array is a very commonly used data type in PHP. Without arrays, it would be difficult for us to effectively manage and process large amounts of data. Commonly used array functions include:

• count(): Returns the length of the array.
• implode(): Convert an array to a string.
• explode(): Convert a string to an array.
• array_merge(): Merge two or more arrays into one array.

File function

In web development, we need to read and write data from the background. At this time, we need to use PHP built-in functions to operate files. Commonly used file functions include:

• fopen(): Open a file.
• fread(): Read content from the file.
• fwrite(): Write the content to the file.
• fclose(): Close the file.

Time function

The time function allows us to process and convert time. Commonly used time functions include:

• time(): Returns the current Unix timestamp.
• date(): Convert Unix timestamp to readable time format.
• strtotime(): Convert readable time format to Unix timestamp.
• mktime(): Returns the Unix timestamp of the specified date and time.

Database function

In Web development, the database is an essential part. Commonly used database functions include:

• mysqli_connect(): connection to the MySQL database.
• mysqli_query(): Execute a MySQL query.
• mysqli_fetch_array(): Gets a row from the result set as an associative array, a numeric array, or both.
• mysqli_close(): Close the MySQL database connection.

In short, PHP built-in functions are essential tools for developers. They can speed up the development process and improve code readability and maintainability. Both beginners and experienced developers should be familiar with using these functions.

The above is the detailed content of PHP built-in functions, essential tools. For more information, please follow other related articles on the PHP Chinese website!