During PHP development, type conversion is a common operation. As a common tool for converting variables into strings, the strval function has different performances for different types of values. What happens when we use strval to process NULL values? What details do we need to pay special attention to? This article will discuss this issue.

When using PHP for array operations, many developers are confused by the array_key_exists() function, especially when the key value is null, it still returns true. The reason behind this is actually closely related to the working mechanism of PHP arrays.

How to Use is_null Function in PHP to Check if a Function Returns null? A Detailed Guide

The difference between isset() and is_null()

The array_slice function is a common tool used to extract a sub-array from an array. Its function prototype is as follows:

The parse_url function is a very practical tool for parsing URLs and returning components, such as protocols, host names, paths, etc. The basic usage of the function is as follows:

When using PHP's PDO (PHP Data Objects) for database operations, PDOStatement::fetchObject is a very convenient way to map the result set directly into an object. However, in actual use, we often encounter situations where NULL values ​​exist in the database. If left unprocessed, these NULL values ​​may throw exceptions or unexpected errors in business logic.