Curriculum

PHP Basic

PHP Intro

0/1

PHP Install

0/1

PHP Syntax

0/1

PHP Comments

0/2

PHP Variables

0/4

PHP echo / print

0/3

PHP Data Types

0/7

PHP Strings

0/5

PHP Numbers

0/2

PHP Casting

0/1

PHP Math

0/1

PHP Constants

0/1

PHP Magic Constants

0/1

PHP Operators

0/1

PHP if...Else...Elseif

0/5

PHP switch

0/1

PHP Loops

0/7

PHP Functions

0/6

PHP Arrays

0/11

PHP Superglobals

0/7

PHP RegEx

0/1

PHP Form

0/9

PHP Advanced

0/15

PHP OOP

0/14

MySQL Database

0/14

PHP XML

0/5

PHP Reference

0/276

Text lesson

debug_backtrace()

Example

Produce a PHP backtrace:

<?php
function a($txt) {
    b(“Glenn”);
}
function b($txt) {
    c(“Cleveland”);
}
function c($txt) {
    var_dump(debug_backtrace());
}
a(“Peter”);
?>

Definition and Usage

The debug_backtrace() function creates a PHP backtrace, showing data about the code execution leading up to the point where debug_backtrace() is called. It returns an array of associative arrays, with the following possible elements:

Name	Type	Description
function	string	The name of the current function
line	integer	The line number of the current execution
file	string	The name of the current file
class	string	The name of the current class
object	object	The current instance
type	string	The type of the current call. Possible values include: “->” for method calls “::” for static method calls No value for function calls
args	array	If within a function, it lists the function’s arguments. If within an included file, it lists the names of the included files.

Syntax

debug_backtrace(options, limit);

Parameter Values

Parameter

Description

options

Optional. Allows you to specify a bitmask for the following options:

DEBUG_BACKTRACE_PROVIDE_OBJECT (Determines whether to include the “object” index)
DEBUG_BACKTRACE_IGNORE_ARGS (Determines whether to exclude the “args” index and function/method arguments to conserve memory)

limit

Optional. Restricts the number of stack frames displayed. By default (when limit=0), it shows all stack frames.

Technical Details

Return Value:

An array of associative arrays

PHP Version:

4.3+

PHP Changelog:

 PHP 5.4: Introduced the optional limit parameter.

 PHP 5.3.6: Changed the provide_object parameter to options and added the DEBUG_BACKTRACE_IGNORE_ARGS option.

 PHP 5.2.5: Added the optional provide_object parameter.

 PHP 5.1.1: Included the current object as a possible return element.