


PHP writing login verification code function with calling method, php verification code
The example in this article shares a login verification code function written in PHP for your reference. The specific content is as follows
ShowKey.php
<?php session_start(); //设置COOKIE或Session function esetcookie($name,$str,$life=0){ //本函数将字符串 str 全部变小写字符串使验证码输入不区分大小写----在提交表单进行session比较同样需要次函数转化 $_SESSION[$name]=strtolower($str); } //获取随机字符 此函数区分字符大小写 如果不区分大小写可加入函数strtolower function domake_password($len) { $chars = array( /*"a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z",*/ "0", "1", "2", "3", "4", "5", "6", "7", "8", "9" ); $charsLen = count($chars) - 1; shuffle($chars);// 将数组打乱 $output = ""; for ($i=0; $i<$len; $i++) { $output .= $chars[mt_rand(0, $charsLen)]; //获得一个数组元素 } return $output; } //显示验证码 function ShowKey(){ $key=domake_password(4);//获取随机值 $set=esetcookie("checkkey",$key);//将随机值写入cookie或session //是否支持gd库 if(function_exists("imagejpeg")) { header ("Content-type: image/jpeg"); $img=imagecreate(47,20); $blue=imagecolorallocate($img,102,102,102); $white=ImageColorAllocate($img,255,255,255); $black=ImageColorAllocate($img,71,71,71); imagefill($img,0,0,$blue); imagestring($img,5,6,3,$key,$white); for($i=0;$i<90;$i++) //加入干扰象素 { imagesetpixel($img,rand()%70,rand()%30,$black); } imagejpeg($img); imagedestroy($img); } elseif (function_exists("imagepng")) { header ("Content-type: image/png"); $img=imagecreate(47,20); $blue=imagecolorallocate($img,102,102,102); $white=ImageColorAllocate($img,255,255,255); $black=ImageColorAllocate($img,71,71,71); imagefill($img,0,0,$blue); imagestring($img,5,6,3,$key,$white); for($i=0;$i<90;$i++) //加入干扰象素 { imagesetpixel($img,rand()%70,rand()%30,$black); } imagepng($img); imagedestroy($img); } elseif (function_exists("imagegif")) { header("Content-type: image/gif"); $img=imagecreate(47,20); $blue=imagecolorallocate($img,102,102,102); $white=ImageColorAllocate($img,255,255,255); $black=ImageColorAllocate($img,71,71,71); imagefill($img,0,0,$blue); imagestring($img,5,6,3,$key,$white); for($i=0;$i<90;$i++) //加入干扰象素 { imagesetpixel($img,rand()%70,rand()%30,$black); } imagegif($img); imagedestroy($img); } elseif (function_exists("imagewbmp")) { header ("Content-type: image/vnd.wap.wbmp"); $img=imagecreate(47,20); $blue=imagecolorallocate($img,102,102,102); $white=ImageColorAllocate($img,255,255,255); $black=ImageColorAllocate($img,71,71,71); imagefill($img,0,0,$blue); imagestring($img,5,6,3,$key,$white); for($i=0;$i<90;$i++) //加入干扰象素 { imagesetpixel($img,rand()%70,rand()%30,$black); } imagewbmp($img); imagedestroy($img); } else { //不支持验证码 header("content-type:image/jpeg\r\n"); header("Pragma:no-cache\r\n"); header("Cache-Control:no-cache\r\n"); header("Expires:0\r\n"); $fp = fopen("data/vdcode.jpg","r"); } } ShowKey(); ?>
Calling method:
Copy code The code is as follows:
The above is the entire content of this article. I hope it will be helpful to everyone in learning PHP programming.

php把负数转为正整数的方法:1、使用abs()函数将负数转为正数,使用intval()函数对正数取整,转为正整数,语法“intval(abs($number))”;2、利用“~”位运算符将负数取反加一,语法“~$number + 1”。

实现方法:1、使用“sleep(延迟秒数)”语句,可延迟执行函数若干秒;2、使用“time_nanosleep(延迟秒数,延迟纳秒数)”语句,可延迟执行函数若干秒和纳秒;3、使用“time_sleep_until(time()+7)”语句。

php除以100保留两位小数的方法:1、利用“/”运算符进行除法运算,语法“数值 / 100”;2、使用“number_format(除法结果, 2)”或“sprintf("%.2f",除法结果)”语句进行四舍五入的处理值,并保留两位小数。

判断方法:1、使用“strtotime("年-月-日")”语句将给定的年月日转换为时间戳格式;2、用“date("z",时间戳)+1”语句计算指定时间戳是一年的第几天。date()返回的天数是从0开始计算的,因此真实天数需要在此基础上加1。

php字符串有下标。在PHP中,下标不仅可以应用于数组和对象,还可应用于字符串,利用字符串的下标和中括号“[]”可以访问指定索引位置的字符,并对该字符进行读写,语法“字符串名[下标值]”;字符串的下标值(索引值)只能是整数类型,起始值为0。

方法:1、用“str_replace(" ","其他字符",$str)”语句,可将nbsp符替换为其他字符;2、用“preg_replace("/(\s|\ \;||\xc2\xa0)/","其他字符",$str)”语句。

php判断有没有小数点的方法:1、使用“strpos(数字字符串,'.')”语法,如果返回小数点在字符串中第一次出现的位置,则有小数点;2、使用“strrpos(数字字符串,'.')”语句,如果返回小数点在字符串中最后一次出现的位置,则有。

在php中,可以使用substr()函数来读取字符串后几个字符,只需要将该函数的第二个参数设置为负值,第三个参数省略即可;语法为“substr(字符串,-n)”,表示读取从字符串结尾处向前数第n个字符开始,直到字符串结尾的全部字符。


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