字符串 == 比较类型强转隐患
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//http://php.net/manual/zh/language.operators.comparison.php php 5 var_dump(md5('240610708') == md5('QNKCDZO'));//bool(true) var_dump(md5('aabg7XSs') == md5('aabC9RqS'));//bool(true) var_dump(sha1('aaroZmOk') == sha1('aaK1STfY'));//bool(true) var_dump(sha1('aaO8zKZF') == sha1('aa3OFF9m'));//bool(true) var_dump('0010e2' == '1e3');//10×10^2 = 1×10^3 bool(true) var_dump('0x1234Ab' == '1193131');//bool(true) var_dump('0xABCdef' == ' 0xABCdef');//bool(true) var_dump('0e1' == '0e2'); //bool(true) // php 7 含十六进制字符串不再被认为是数字 http://php.net/manual/zh/migration70.incompatible.php var_dump('0x1234Ab' == '1193131');//bool(false) var_dump('0xABCdef' == ' 0xABCdef');//bool(false) var_dump("0x123" == "291");//bool(false) var_dump(is_numeric("0x123"));//bool(false) >>> md5('240610708') => "0e462097431906509019562988736854" >>> md5('QNKCDZO') => "0e830400451993494058024219903391" // php 是弱语言，会自动判断数据类型,0eXXXXXXXXXX 转成 0 了 //来自文档：如果比较一个数字和字符串或者比较涉及到数字内容的字符串，则字符串会被转换为数值并且比较按照数值来进行。此规则也适用于 switch 语句。当用 === 或 !== 进行比较时则不进行类型转换，因为此时类型和数值都要比对。 >>> md5('QNKCDZO')==0 => true >>> md5('240610708')==0 => true // 使用 === 判断 官方都建议直接用password_hash加密 var_dump(md5('240610708') === md5('QNKCDZO'));//bool(false) //把你的密码设成 0x1234Ab，然后退出登录再登录，换密码 1193131 登录，如果登录成功，那么密码绝对是明文保存的。 //同理，密码设置为 240610708，换密码 QNKCDZO 登录能成功，那么密码没加盐直接md5保存的。
ps: php 7 优化和不兼容
PDO bindParam 要求第二个参数是一个引用变量
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//http://www.laruence.com/2012/10/16/2831.html $dbh = new PDO('mysql:host=localhost;dbname=test', "test"); $query = <<<QUERY INSERT INTO `user` (`username`, `password`) VALUES (:username, :password); QUERY; $statement = $dbh->prepare($query); $bind_params = array(':username' => "laruence", ':password' => "weibo"); foreach( $bind_params as $key => $value ){ $statement->bindParam($key, $value); } $statement->execute(); //期望执行 sql INSERT INTO `user` (`username`, `password`) VALUES ("laruence", "weibo"); // 实际执行 sql INSERT INTO `user` (`username`, `password`) VALUES ("weibo", "weibo"); //第一次循环 $value = $bind_params[":username"]; $statement->bindParam(":username", &$value); //此时, :username是对$value变量的引用 //第二次循环 $value = $bind_params[":password"]; //oops! $value被覆盖成了:password的值 $statement->bindParam(":password", &$value); // 解决 foreach( $bind_params as $key => &$value ) { //注意这里 $statement->bindParam($key, $value); } return $statement->execute($params);
PHP 引用
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//https://glot.io/snippets/estgofa359 $arr = range(1,3); foreach($arr as &$v){ } foreach($arr as $v){ } print_r($arr);//[1,2,2] // 解决一 $arr = range(1,3); foreach($arr as &$v){ } unset($v); foreach($arr as $v){ } print_r($arr);//[1,2,3] // 解决二 $arr = range(1,3); foreach($arr as &$v){ } foreach($arr as $v2){ } print_r($arr);//[1,2,3] // 解决三 $arr = range(1,3); foreach($arr as &$v){ } foreach($arr as &$v){ } print_r($arr);//[1,2,3]
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//https://glot.io/snippets/estgpi43bc $arr1 = array(1 => "one", "2" => "two", 3 => "three"); $arr2 = array(2 => "new two", 3 => "new three"); print_r($arr1 + $arr2); Array ( [1] => one [2] => two [3] => three ) print_r(array_merge($arr1, $arr2)); Array ( [0] => one [1] => two [2] => three [3] => new two [4] => new three )
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http://php.net/manual/zh/language.types.float.php var_dump(15702>=(157.02*100));//bool(false) var_dump(11111>=(111.11*100));//bool(true) var_dump(bcsub(15702,(157.02*100)) >= 0);//bool(true) if(abs(15702-(157.02*100)) < 0.001) { echo "相等"; } else { echo "不相等"; } $f = 0.58; var_dump(intval($f * 100)); //57 0.58 * 100 = 57.999999999...
in_array
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//https://glot.io/snippets/esth249n0y $arr = ['a', 'pro' => 'php', 8, true]; var_dump(in_array(2, $arr)); // bool(true) var_dump(in_array('b', $arr)); // bool(true) var_dump(in_array(0, $arr)); // tbool(true) var_dump(in_array(null, $arr)); // bool(false) var_dump(in_array(2, $arr, true)); // bool(false) var_dump(in_array(0, $arr, true)); // bool(false)
strpos
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//https://glot.io/snippets/esthlvjtki function getReferer($link) { $refMap = [ 'baidu' => '百度', 'sougou' => '搜狗', '360' => '360', 'google' => '谷歌' ]; foreach ($refMap as $key => $value) { if (strpos($link, $key) !== false) { return $value; } } return '其他'; } // https://secure.php.net/manual/zh/function.strpos.php 如果 needle 不是一个字符串，那么它将被转换为整型并被视为字符的顺序值。 echo getReferer('https://www.google.com/search?workd=google');//360 // 解决 function getReferer($link) { $refMap = [ 'baidu' => '百度', 'sougou' => '搜狗', '360' => '360', 'google' => '谷歌' ]; foreach ($refMap as $key => $value) { if (mb_strpos($link, $key) !== false) { //if (strpos($link, strval($key)) !== false) { return $value; } } return '其他'; }
cURL 文件上传
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//PHP的cURL支持通过给CURL_POSTFIELDS传递关联数组（而不是字符串）来生成multipart/form-data的POST请求 http://php.net/manual/zh/curlfile.construct.php if (class_exists('\CURLFile')) { $field = array('fieldname' => new \CURLFile(realpath($filepath))); } else { $field = array('fieldname' => '@' . realpath($filepath)); }
