php中技巧注意笔记2

PHP5中，有个新的验证方法，CTYPE，可以专门针对字符串进行验证

如

<?php

    if (!ctype_alnum($_GET['login'])) {

       echo "输入项必须为英文字符或数字0-9。";

    }

    if (!ctype_alpha($_GET['captcha'])) {

       echo "输入项必须为英文字符（大小写均可）";

    }

    if (!ctype_xdigit($_GET['color'])) {

       echo "输入项必须填写一个16进制数字。";

    }

?>

还有检查大小写的

<?php

$strings = array('aac123', 'qiutoas', 'QASsdks');

foreach ($strings as $testcase) {

    if (ctype_lower($testcase)) {

        echo "The string $testcase consists of all lowercase letters.\n";

    } else {

        echo "The string $testcase does not consist of all lowercase letters.\n";

    }

}

?>

检查空白字符的

<?php

$strings = array('string1' => "\n\r\t", 'string2' => "\narf12", 'string3' => '\n\r\t');

foreach ($strings as $name => $testcase) {

    if (ctype_space($testcase)) {

        echo "The string '$name' consists of all whitespace characters.\n";

    } else {

        echo "The string '$name' does not consist of all whitespace characters.\n";

    }

}

?>