Error code classification and solutions in PHP language development

PHP is a widely used open source scripting language. It is widely loved by developers because of its simplicity, ease of expansion and excellent performance. However, in actual development, we will inevitably encounter various errors, which may prevent our program from running normally or even cause the system to crash. In order to better handle these errors, we need to understand the error code classification and solutions in PHP language development.

1. PHP error code classification

Common error messages in PHP language development can be divided into the following categories:

1. Syntax Errors

Syntax errors are the most common type of errors among PHP programmers. When PHP parses and executes, if it encounters an incomprehensible syntax structure, a syntax error will occur.

This kind of error message is usually displayed directly on the browser, and the problem line can be found in the PHP encoder.

For example, the following statement will cause a syntax error in PHP:

echo "Hello World!"
?>

Please note that without the semicolon, this code will throw a syntax error exception.

2. Runtime Errors

Runtime errors are one of the most common problems faced by PHP programmers during the development process. They usually refer to errors that occur while the program is running, such as dividing by zero, function not existing, etc.

These errors can cause system crashes and must be handled with extreme caution.

For example:

$a=3;
$b=0;
$c=$a/$b;
echo $c;
?>

The above code will cause a divide-by-zero runtime error.

3. Logic Errors

Logic errors refer to errors where there are no obvious errors in program execution, but the results do not meet design expectations. Unlike syntax errors and run-time errors, they usually do not give any warning or error message.

Logical errors are usually caused by logical errors in the code written by programmers. Therefore, when writing code, we must carefully check whether the code meets the logical requirements of the program.

For example:

$a=3;
$b=4;
$c=$a $b;
echo " a b=$c";
?>

The expected result of the above code is "a b=7", but if the programmer mistakenly uses the minus sign in the code, there will be problems with the output result .

2. Solution

In PHP language development, we can solve the above error message in the following ways:

1. Debugging tool

Debugging tool Is a valid debugging type that can be used to find and resolve errors. The PHP language provides many such tools, such as Xdebug, etc.

2.Exception handling

Exception handling is a mechanism for handling program errors, which allows us to catch and handle exceptions when an error occurs.

For example:

try {
$result = 10 / 0;
} catch (Exception $e) {
echo 'Caught exception: ', $e- >getMessage(), "
";
}

When $ b equals 0, program execution will throw an exception. Then, inside the try block, we catch and handle the exception using the catch block.

3. Logging

In order to better record error information and help debugging, we can log error messages to a file or database. PHP provides many different logging methods, such as standard error logging (syslog), telemetry error logging (Sentry, Airbrake), and many more.

For example:

function log_error($error_message) {

$date = date('m/d/Y h:i:s a', time());
$log_message = "$date $error_message

";

error_log($log_message, 3, '/var/log/error_log');

}
?> ;

The above code writes the error message to a file named error_log.

Summary:

In PHP language development, error classification is a very important knowledge point. It can help us better troubleshoot and handle errors, and can provide us with direction and support in actual development. We can better understand the error code classification and solutions in PHP language development by learning the above classifications and solutions.

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