PHP Types of Errors

PHP's internal Error types are represented by classes that are inherited from Error class. The Error class implements Throwable interface and provides a structured way to handle different types of runtime errors.

Error Class Properties

• message − The error message
• code − The error code
• file − The filename where the error happened
• line − The line where the error happened

Error Class Methods

• __construct() − Construct the error object
• getMessage() − Gets the error message
• getPrevious() − Returns previous Throwable
• getCode() − Gets the error code
• getFile() − Gets the file in which the error occurred
• getLine() − Gets the line in which the error occurred
• getTrace() − Gets the stack trace
• getTraceAsString() − Gets the stack trace as a string
• __toString() − String representation of the error
• __clone() − Clone the error

Error Class Hierarchy

Common Error Types

ArithmeticError

Thrown when an error occurs while performing mathematical operations ?

<?php
try {
    $result = 1 / 0;
} catch (DivisionByZeroError $e) {
    echo "Error: " . $e->getMessage();
}
?>

Error: Division by zero

TypeError

Occurs when a value is not of the expected type ?

<?php
function addNumbers(int $a, int $b): int {
    return $a + $b;
}

try {
    echo addNumbers("hello", 5);
} catch (TypeError $e) {
    echo "Error: " . $e->getMessage();
}
?>

Error: addNumbers(): Argument #1 ($a) must be of type int, string given

ParseError

Thrown when PHP code contains syntax errors. Here's an example of catching parse errors in evaluated code ?

<?php
try {
    eval('echo "Missing semicolon"');
} catch (ParseError $e) {
    echo "Parse Error: " . $e->getMessage();
}
?>

Parse Error: syntax error, unexpected end of file

Conclusion

PHP's Error class hierarchy provides a structured approach to error handling with specific error types for different scenarios. Understanding these error types helps in writing more robust PHP applications with proper exception handling.