Introduction to the use of debug function debug_backtrace in PHP

debug_backtrace() is a very low-key function, and few people have paid attention to it. This article mainly introduces you to the use of the debug function debug_backtrace in PHP. The article introduces it in detail through example code, which is very helpful to everyone. Studying or working has certain reference learning value. Friends who are interested should follow the editor to learn together.

Preface

If we want to know who called a certain method? debug_backtrace can solve it. debug_backtrace() can print out the calling process of a page, where it comes from and where it goes. Sometimes we want to know the call stack of this function or method, that is, how it is called level by level. If you arrive, you can use PHP's debug_backtrace function to print it, like this:

Sample code

public function update(Request $request, $id)
{
 dd(debug_backtrace());
 $getGameID = function ($request) {
 if (!$request->game_id) {
  return 1000 + intval($request->id);
 }
 return $request->game_id;
 };
 
 $previews = $this->getGamePreviews($request->game_preview);
 
 $request->merge([
 'game_preview' => json_encode($previews),
 'game_id' => $getGameID($request)
 ]);
 EgretGame::where('id', $id)->update($request->except(['_token', '_method']));
 return redirect()->route('egretgame.index')->with('success', '编辑成功！');
}

You can control the number of stack levels that need to be traced back. The first parameter of debug_backtrace defaults to a constant

DEBUG_BACKTRACE_PROVIDE_OBJECT

, which indicates that the information of this object is displayed. The second parameter is used to control the number of stacks to backtrace. The default is all.

The effect is as shown in the figure, and the relationship between the calling levels is clear at a glance:

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