Include does not work when the php file name and class name are the same?

File name: Originally ValidationCode.php
After changing to validate.php, the verification code can be displayed normally.
The browser requests the code.php file to display the verification code

<code>&lt;?php
    class ValidationCode{
        private $width;
        private $height;
        private $num_chars;
        private $image;
        const BORDER = 1;

        function __construct($width=60,$height=20,$num_chars=4){
            $this-&gt;width = $width;
            $this-&gt;height = $height;
            $this-&gt;num_chars = $num_chars;
        }
        
        function showImage(){
            $this-&gt;createImage();
            $this-&gt;drawBorder();
            $this-&gt;drawChars();
            $this-&gt;outPic();
        }
        
        //create canvas
         function createImage(){
            $this-&gt;image = imagecreate($this-&gt;width,$this-&gt;height);
            //$rand_color = imagecolorallocate($this-&gt;image,rand(0,255),rand(0,255),rand(0,255));
            $back = imagecolorallocate($this-&gt;image,0,0,0);
            $border = imagecolorallocate($this-&gt;image,255,255,255);
            imagefill($this-&gt;image,0,0,$back);
            //imagefilledrectangle($thid-&gt;image,self::BORDER,self::BORDER,$this-&gt;width-self::BORDER,$this-&gt;height-self::BORDER,$border);
            //imageline($this-&gt;image,1,1,100,100,$rand_color);
            //$this-&gt;outPic();
        }

        //draw border
        private function drawBorder(){
            $outer_bg_color = imagecolorallocate($this-&gt;image,0,0,0);
            $inner_bg_color = imagecolorallocate($this-&gt;image,255,255,255);
            imagefill($this-&gt;image,0,0,$outer_bg_color);
            imagefilledrectangle($this-&gt;image,self::BORDER,self::BORDER,$this-&gt;width-self::BORDER-1,$this-&gt;height-self::BORDER-1,$inner_bg_color);

        }        
    
        //create char content
          function createChar(){
            $rand_ascii="";
            $rand_type = rand(0,2);
            switch($rand_type){
                case 0:
                    $rand_ascii = rand(48,57);  
                   break;
                case 1:
                     $rand_ascii = rand(65,90);
                   break;
                case 2:
                     $rand_ascii = rand(97,122);
                   break;
            }
            $rand_str = sprintf("%c",$rand_ascii);
            return $rand_str;
        }
    
    
    
        //draw char
         private function drawChars(){
            $x = $this-&gt;width/$this-&gt;num_chars+1;
            $y = $this-&gt;height/2;
            for($index = 0; $index&lt;$this-&gt;num_chars; $index++){
                $rand_color = imagecolorallocate($this-&gt;image,rand(0,255),rand(0,255),rand(0,255));
                imagechar($this-&gt;image,3,$x*$index+2,$y-$y/2,$this-&gt;createChar(),$rand_color);
            }
        }

        //out pic
        private function outPic(){
            header("content-type:image/png");
            imagepng($this-&gt;image);
        }
        

         function __destruct(){
             imagedestroy($this-&gt;image);
         }
    }
    
    /*$code = new ValidationCode();
    //echo $code-&gt;createChar();
    $code-&gt;showImage();*/
?&gt;</code>

code.php

<code>&lt;?php
     require_once("validate.php");
    $code = new ValidationCode();
    //echo $code-&gt;createChar();
    $code-&gt;showImage();
  ?&gt;</code>

This question has been closed, reason: I have found the cause of the problem myself

Reply content:

File name: Originally ValidationCode.php
After changing to validate.php, the verification code can be displayed normally.
The browser requests the code.php file to display the verification code

<code>&lt;?php
    class ValidationCode{
        private $width;
        private $height;
        private $num_chars;
        private $image;
        const BORDER = 1;

        function __construct($width=60,$height=20,$num_chars=4){
            $this-&gt;width = $width;
            $this-&gt;height = $height;
            $this-&gt;num_chars = $num_chars;
        }
        
        function showImage(){
            $this-&gt;createImage();
            $this-&gt;drawBorder();
            $this-&gt;drawChars();
            $this-&gt;outPic();
        }
        
        //create canvas
         function createImage(){
            $this-&gt;image = imagecreate($this-&gt;width,$this-&gt;height);
            //$rand_color = imagecolorallocate($this-&gt;image,rand(0,255),rand(0,255),rand(0,255));
            $back = imagecolorallocate($this-&gt;image,0,0,0);
            $border = imagecolorallocate($this-&gt;image,255,255,255);
            imagefill($this-&gt;image,0,0,$back);
            //imagefilledrectangle($thid-&gt;image,self::BORDER,self::BORDER,$this-&gt;width-self::BORDER,$this-&gt;height-self::BORDER,$border);
            //imageline($this-&gt;image,1,1,100,100,$rand_color);
            //$this-&gt;outPic();
        }

        //draw border
        private function drawBorder(){
            $outer_bg_color = imagecolorallocate($this-&gt;image,0,0,0);
            $inner_bg_color = imagecolorallocate($this-&gt;image,255,255,255);
            imagefill($this-&gt;image,0,0,$outer_bg_color);
            imagefilledrectangle($this-&gt;image,self::BORDER,self::BORDER,$this-&gt;width-self::BORDER-1,$this-&gt;height-self::BORDER-1,$inner_bg_color);

        }        
    
        //create char content
          function createChar(){
            $rand_ascii="";
            $rand_type = rand(0,2);
            switch($rand_type){
                case 0:
                    $rand_ascii = rand(48,57);  
                   break;
                case 1:
                     $rand_ascii = rand(65,90);
                   break;
                case 2:
                     $rand_ascii = rand(97,122);
                   break;
            }
            $rand_str = sprintf("%c",$rand_ascii);
            return $rand_str;
        }
    
    
    
        //draw char
         private function drawChars(){
            $x = $this-&gt;width/$this-&gt;num_chars+1;
            $y = $this-&gt;height/2;
            for($index = 0; $index&lt;$this-&gt;num_chars; $index++){
                $rand_color = imagecolorallocate($this-&gt;image,rand(0,255),rand(0,255),rand(0,255));
                imagechar($this-&gt;image,3,$x*$index+2,$y-$y/2,$this-&gt;createChar(),$rand_color);
            }
        }

        //out pic
        private function outPic(){
            header("content-type:image/png");
            imagepng($this-&gt;image);
        }
        

         function __destruct(){
             imagedestroy($this-&gt;image);
         }
    }
    
    /*$code = new ValidationCode();
    //echo $code-&gt;createChar();
    $code-&gt;showImage();*/
?&gt;</code>

code.php

<code>&lt;?php
     require_once("validate.php");
    $code = new ValidationCode();
    //echo $code-&gt;createChar();
    $code-&gt;showImage();
  ?&gt;</code>

Test: Entry Code

<code>&lt;?php
require_once("ValidationCode.php");//include_once("ValidationCode.php");
$code = new ValidationCode();
//echo $code-&gt;createChar();
$code-&gt;showImage();</code>

File name:

Test results:

Conclusion: The file name has nothing to do with the class name when including. The result is OK. I don't know why yours can't. But I tested it and it's OK.

It’s really fake! References to file names and class names do not work, so magical! Are there any error messages