Use php to implement addition and subtraction verification code

This article mainly introduces the addition and subtraction verification code code implemented in PHP. You can use addition and subtraction within 10 to generate pictures. Friends in need can refer to it

<?php
/*图片验证码文件，加减计算方式*/
class ImageCode{

 private $Jiashu  = 0;        //加数或者减数
 private $JianShu = 0;        //被加数或者被减数
 private $YunSuan = &#39;&#39;;       //运算符
 private $DeShu   = 0;        //得数
 private $String  = &#39;&#39;;       //字符串样式
 private $Img;                //图片对象
 private $Width   = 100;      //图片宽度
 private $Height  = 50;       //图片高度
 private $Ttf     = &#39;Num.ttf&#39;;//字体文件
 private $Session = &#39;code&#39;;   //Session变量

 private function JiaShu(){
  header(&#39;Content-type:image/png&#39;);
  $this -> Jiashu  = rand(1, 10);
  $this -> JianShu = rand(1, 10);
  $this -> YunSuan= $this -> Jiashu > $this -> JianShu ? &#39;-&#39; : &#39;+&#39;;
  $this -> DeShu   = $this -> Jiashu > $this -> JianShu ? $this -> Jiashu - $this -> JianShu : $this -> Jiashu + $this -> JianShu;
 }

 public function Show( $W = 100, $H = 50, $T = &#39;Num.ttf&#39;, $Code = &#39;code&#39; ){
  $this -> JiaShu();
  $this -> String = $this -> Jiashu . $this -> YunSuan . $this -> JianShu . &#39;= ? &#39;;
  $this -> Width  = $W;
  $this -> Height = $H;
  $this -> Ttf    = $T;
  $this -> Session= $Code;
  session_start();
  $_SESSION[$this -> Session] = $this -> DeShu;
  $this -> Images();
 }

 private function Images(){
  $this -> Img = imagecreate($this -> Width, $this -> Height);
  $background_color = imagecolorallocate ($this -> Img, 255, 255, 255);
  imagecolortransparent($this -> Img, $background_color);
        imagettftext($this -> Img, 14, 0, 1, 20, imagecolorallocate ($this -> Img, 0, 0, 0), $this -> Ttf, $this -> String );
  $this -> EchoImages();
 }

 private function EchoImages(){
  imagepng($this -> Img);
  imagedestroy($this -> Img);
 }

}
$ImageCode = new ImageCode;
$ImageCode -> Show(130, 35, &#39;Num.ttf&#39;, &#39;code&#39;);

The above is the entire content of this article. I hope it will be helpful to everyone's learning. For more related content, please pay attention to the PHP Chinese website!

Related recommendations:

About the function code for finding polynomial derivatives in PHP

A summary of some methods for intercepting strings in PHP

The above is the detailed content of Use php to implement addition and subtraction verification code. For more information, please follow other related articles on the PHP Chinese website!