Php exception handling

Php error handling 1. view the source code of the error type and copy it to the clipboard to print help; E_ALL & nbsp; //-all errors and warnings (excluding E_STRICT ). & nbsp; E_ERRO php error handling
I. types of errors

View source code Copy to clipboard printing help
; E_ALL //-all errors and warnings (excluding E_STRICT ).
; E_ERROR //-fatal runtime error
; E_RECOVERABLE_ERROR //-almost fatal runtime error
; E_WARNING //-warning during running (non-fatal error)
; E_PARSE //-parsing error during compilation
; E_NOTICE //-runtime prompts, which are often caused by bugs in the code.
; E_STRICT //-runtime prompt, which can give PHP suggestions to improve your code.
; E_CORE_ERROR //-fatal error during PHP initialization startup.
; E_CORE_WARNING // non-fatal error during PHP initialization startup.
; E_COMPILE_ERROR //-fatal compilation error.
; E_COMPILE_WARNING //-compilation error (non-fatal error ).
; E_USER_ERROR //-user error message.
; E_USER_WARNING //-user warning information.
; E_USER_NOTICE //-user prompt information .;
II. display of php. ini configuration errors

View source code Copy to clipboard printing help
// 1. the error message is output to the client (this is more convenient when debugging code)
Display_errors = ON

// 2. the error message will not be output to the user end (remember to change it to off when it is finally published to the user)
Display_errors = OFF
3. php. ini error output configuration recommendation

View source code Copy to clipboard printing help
// 1. output all information.
Error_reporting = E_ALL

// 2. output all errors except the prompt.
Error_reporting = E_ALL &~ E_NOTICE

// 3. all ERROR messages are output.
Error_reporting = E_COMPILE_ERROR | E_RECOVERABLE_ERROR | E_ERROR | E_CORE_ERROR
4. complete error levels in php

1. error level list

Value error code
1 E_ERROR
2 E_WARNING
4 E_PARSE
8 E_NOTICE
16 E_CORE_ERROR
32 E_CORE_WARNING
64 E_COMPILE_ERROR
128 E_COMPILE_WARNING
256 E_USER_ERROR
512 E_USER_WARNING
1024 E_USER_NOTICE
2047 E_ALL
2048 E_STRICT
4096 E_RECOVERABLE_ERROR
2. use error_reporting ([int level]) to adjust the error level

Example

View source code Copy to clipboard printing help
Error_reporting (0); // disable all ERROR DISPLAY

Error_reporting (E_ERROR | E_WARNING | E_PARSE );

Error_reporting (E_ERROR | E_WARNING | E_PARSE | E_NOTICE );

Error_reporting (E_ALL ^ E_NOTICE); // php. ini error value.

Error_reporting (E_ALL); // displays all error messages.
V. Custom Error function processing

1. use the set_error_handler () function to declare an error handling function to the system.

2. trigger_error () function can trigger an error

Example

View source code Copy to clipboard printing help
Function myErrorHandler ($ errno, $ errstr, $ errfile, $ errline)
{
Switch ($ errno ){
Case E_USER_ERROR:
Echo" My ERROR[$ Errno] $ errstr \ n ";
Echo "Fatal error in line $ errline of file $ errfile ";
Echo ", PHP". PHP_VERSION. "(". PHP_ OS. ") \ n ";
Echo "Aborting... \ n ";
Exit (1 );
Break;
Case E_USER_WARNING:
Echo" My WARNING[$ Errno] $ errstr \ n ";
Break;
Case E_USER_NOTICE:
Echo" My NOTICE[$ Errno] $ errstr \ n ";
Break;
Default:
Echo "Unknown error type: [$ errno] $ errstr \ n ";
Break;
}
}

// Define the error handling function.
Set_error_handler ("myErrorHandler ");

// Assume that a negative age occurs, which is obviously incorrect.
$ Age =-100;

If ($ age <0 ){
// Trigger an error;
Trigger_error ("age you input must> = 0", E_USER_ERROR );
}