php settings error

During the development process of PHP, you may encounter some errors. In order to better eliminate these errors, we need to set up PHP's error reporting mechanism. This article will introduce how to set up PHP error reporting, as well as some common error types and solutions.

1. How to set up PHP error reporting

In PHP, we can set up error reporting by modifying error_reporting and display_errors in the php.ini file.

The error_reporting value determines which error types are reported by PHP. It can be set to an integer or a string. An integer representing a binary mask of this error type. For example:

error_reporting(E_ERROR | E_WARNING);

This means that only E_ERROR and E_WARNING errors are reported.

The string represents the name of the error type. For example:

error_reporting("E_ERROR | E_WARNING");

This also means that only E_ERROR and E_WARNING errors are reported.

display_errors determines whether to display errors. It can be set to On or Off. If set to On, error messages are sent to the browser. For example:

display_errors = On

If set to Off, error messages will not be sent to the browser. For example:

display_errors = Off

If you are in the development stage, it is recommended to set error_reporting to E_ALL and set display_errors to On so that you can detect and debug errors in time when they occur.

2. Common error types and solutions

1. E_ERROR

E_ERROR represents a fatal error. When this error occurs, the script stops executing. This error is usually caused by syntax errors, runtime errors, or problems such as exceeding memory limits. For example:

PHP Parse error: syntax error, unexpected end of file

This error is caused by a missing closing bracket in the code. The solution is to find the missing closing bracket and add it.

2. E_WARNING

E_WARNING indicates a non-fatal error. When this error occurs, the script continues execution. This error is usually caused by insufficient number of parameters, use of undefined functions or variables, etc. For example:

Warning: Division by zero

This error is caused by dividing a number by zero. The solution is to check whether the dividend is zero or change the dividend to a non-zero value.

3. E_NOTICE

E_NOTICE indicates a warning error. When this error occurs, the script continues execution. This error is usually caused by the use of undefined constants, undefined variables, uninitialized variables, use of undefined arrays, etc. For example:

Notice: Undefined variable

This error is caused by using an undefined variable. The solution is to use the isset() function to check if the variable has been defined.

4. E_PARSE

E_PARSE indicates a syntax error. When this error occurs, the script stops executing. This error is usually caused by syntax errors. For example:

Parse error: syntax error, unexpected T_VARIABLE

This error is caused by using an unrecognized variable name in the code. The solution is to find the erroneous line of code and modify it.

5. E_COMPILE_ERROR

E_COMPILE_ERROR indicates a compile-time error. When this error occurs, the script stops executing. This error is usually caused by an error occurring while compiling the code. For example:

Fatal error: Call to undefined function

This error is caused by calling an undefined function. The solution is to check whether the function name is correct or whether the file containing the function is included.

6. The difference between E_WARNING and E_NOTICE

E_WARNING and E_NOTICE are both warning errors. The difference between them is that E_WARNING is more severe. Usually, E_WARNING indicates a logical error in the code or a lack of important data, which needs to be resolved in time. E_NOTICE represents a general problem with the code, which will not cause the code to crash, but it also needs to be resolved in time.

7. Other error types

In addition to the above common error types, there are some other error types, such as E_DEPRECATED (indicating that a deprecated method or function) and E_USER_ERROR (indicates a user-defined error). These error types are uncommon, but require prompt resolution when encountered.

3. Summary

Setting up PHP’s error reporting mechanism can help us discover and resolve errors in the code in a timely manner. During development, it is recommended to set error_reporting to E_ALL and display_errors to On. Common error types include E_ERROR, E_WARNING, E_NOTICE, E_PARSE, E_COMPILE_ERROR, etc. When encountering an error, you need to carefully analyze the error message and take appropriate solutions.

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