What are the uses of PHP functions returning exception objects?

PHP functions can handle errors by throwing exception objects. These objects encapsulate error information, making code cleaner and easier to maintain, and allow errors to propagate up the call stack. Custom exception objects can be used to define application-specific error types. PHP provides a variety of built-in exception object types, and you can also create custom exception objects. Exceptions can be caught and handled using the try-catch statement.

PHP function returns exception object: usage overview

Introduction

PHP function Error conditions can be handled by throwing exception objects. This allows code to handle errors clearly and concisely, and improves maintainability and readability.

Usage

// 抛出自定义异常对象
throw new MyException('错误信息');

// 抛出内建异常对象
throw new RuntimeException('运行时错误');

Benefits

• Code clarity: Exception object will error message Encapsulating it in an object makes error handling code more readable and maintainable.
• Improve efficiency: Exception handling allows exceptions to be thrown directly from the error location, avoiding extensive error checking using if statements.
• Error propagation: Exception objects can be propagated up the call stack, allowing callers to easily handle errors.
• Customizability: Custom exception objects allow the definition of application-specific error types to facilitate the handling of specific error conditions.

Practical case

Verify input

class InvalidInputException extends Exception {}

function validateInput(string $input)
{
    if (empty($input)) {
        throw new InvalidInputException('输入不能为空');
    }
}

Database operation

class DatabaseException extends RuntimeException {}

function queryDatabase(string $query)
{
    try {
        // 查询数据库
    } catch (PDOException $e) {
        throw new DatabaseException($e->getMessage(), $e->getCode());
    }
}

Types of exception objects

PHP provides a variety of built-in exception object types, including:

• Exception: Basic exception Class
• RuntimeException: Runtime exception class
• TypeError: Type error exception class
• InvalidArgumentException : Illegal parameter exception class

Custom exception object

Custom exception objects can also be created to represent application-specific error conditions.

class MyCustomException extends Exception {}

// 使用自定义异常对象
throw new MyCustomException('自定义错误');

Catch exceptions

You can use the try-catch statement to capture and handle exceptions:

try {
    // 可能会抛出异常的代码
} catch (Exception $e) {
    // 处理异常
}

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