How to handle PHP function parameter type indeterminacy?

For PHP function parameter types that are uncertain, you can solve it through the following steps: use type hints to specify the expected type in the function declaration to enhance code readability and documentation. Use type checking to verify that the actual type of a parameter matches the expected type. Handle mismatch situations based on the check results, such as throwing exceptions or providing different handling methods.

How to deal with the situation where the type of function parameters in PHP is uncertain

In PHP, the type of function parameters is not always determined of. For this situation, you can use type hinting and type checking.

Type hints

Type hints allow you to specify the expected types of parameters in a function declaration. This helps document code and improve readability. For example:

function add(int $a, int $b): int
{
    return $a + $b;
}

This declaration indicates that the add() function expects two integer parameters and will return an integer.

Type checking

Type checking is the process of ensuring that the actual type of a function parameter matches the expected type. You can use the gettype() function to get the type of a variable and then compare it to the expected type.

function add(int $a, int $b): int
{
    if (gettype($a) !== 'integer' || gettype($b) !== 'integer') {
        throw new InvalidArgumentException('Argument types must be integers');
    }

    return $a + $b;
}

In the above example, the add() function will check whether the parameter is an integer and throw an exception if the condition is not met.

Practical case

Suppose you have a parseCSV() function for parsing CSV files. However, the type of file input is unknown. You can use type checking to ensure that the input is a string:

function parseCSV(string $input): array
{
    if (gettype($input) !== 'string') {
        throw new InvalidArgumentException('Input must be a string');
    }

    // 解析 CSV 文件并返回数据
}

By using type hints and checks in your code, you can improve the robustness and reliability of your application and prevent unexpected errors.

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