php jquery verification code_PHP tutorial

This tutorial mainly uses jquery's ajax to implement advance verification of jquery php verification code without refreshing. ​

This tutorial mainly uses jquery's ajax to realize the advance verification operation of the jquery php tutorial verification code code without refreshing.

//Calling this page, if the following formula is true, generate a verification code image
if($_get['action']=='verifycode'){
rand_create();
}
//Verification code image generation

function rand_create(){
//Notify the browser that png images will be output

header('content-type: image/png');

//Prepare the random number generator seed
srand((double)microtime()*1000000);
//Prepare the relevant parameters of the image
$im = imagecreate(62,20);
$black = imagecolorallocate($im, 0,0,0); //rgb black identifier
$white = imagecolorallocate($im, 255,255,255); //rgb white identifier
$gray = imagecolorallocate($im, 200,200,200); //rgb gray identifier
//Start drawing
Imagefill($im,0,0,$gray);
While(($randval=rand()%100000)<10000);{
​​​​ //Draw the four-digit integer verification code into the picture
Session_start();
$_session['login_check_num'] = $randval;
Imagestring($im, 5, 10, 3, $randval, $black);
}
//Add interference pixels
for($i=0;$i<200;$i++){
          $randcolor = imagecolorallocate($im,rand(0,255),rand(0,255),rand(0,255));
imagesetpixel($im, rand()%70, rand()%30, $randcolor);
}
//Output verification image
Imagepng($im);
//Destroy image identifier
Imagedestroy($im);
}

?>
The verification code displayed on the static page is:

Verification code:
                                                                       The ajax verification code for the jquery part is:
$.post("session.php",

Function(data){
If(data === "1"){
          //do...
}else{
                                                                                                                                                                    }
);

The php page that assists in ajax verification is called session.php, and its code is:

session_start(); //Check verification code

echo 1;
}else{
echo 0;
exit();
}


?>