PHP error handling functions - debug_backtrace()

Last update on May 28 2022 12:23:19 (UTC/GMT +8 hours)

Introduction

The debug_backtrace() function is used to generate a PHP backtrace.

Syntax:

debug_backtrace(provide_object )

Parameters:

provide_object: Specifies whether the object index is to be populated or not. Type of provide_object is boolean.

Return Values:

debug_backtrace() function returns an associative array. Here is a list of the possible returned elements :

Name	Type	Description
function	string	Name of the current function.
line	integer	The Current line number.
file	string	The Current file name.
class	string	The Current class name.
object	object	The Current object name.
type	string	Specifies the current call type.
		For a method call.	-> is returned.
		For a static method call.	:: is returned.
		For a function call.	nothing is returned.
args	array	If inside a function.	this lists the functions arguments.
args	array	If inside an included file.	this lists the included file name(s).

Example:

<?php
function w3r($str)
{
    echo "We are learning:".$str."<br />";
    var_dump(debug_backtrace());
}
w3r('php');
?>

The above code displays this output:

We are learning:php
array(1) {
  [0]=>
  array(4) {
    ["file"]=>
    string(92) "C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\php\debug-backtrace-example.php"
    ["line"]=>
    int(8)
    ["function"]=>
    string(3) "w3r"
    ["args"]=>
    array(1) {
      [0]=>
      &string(3) "php"
    }
  }
}

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Next: debug_print_backtrace()

PHP: Tips of the Day

How to Sort Multi-dimensional Array by Value?

Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:

Example:

function sortByOrder($a, $b) {
    return $a['order'] - $b['order'];
}

usort($myArray, 'sortByOrder');

Starting in PHP 5.3, you can use an anonymous function:

usort($myArray, function($a, $b) {
    return $a['order'] - $b['order'];
});

And finally with PHP 7 you can use the spaceship operator:

usort($myArray, function($a, $b) {
    return $a['order'] <=> $b['order'];
});

To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.

usort($myArray, function($a, $b) {
    $retval = $a['order'] <=> $b['order'];
    if ($retval == 0) {
        $retval = $a['suborder'] <=> $b['suborder'];
        if ($retval == 0) {
            $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder'];
        }
    }
    return $retval;
});

If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual

Ref : https://bit.ly/3i77vCC