isset

Using if(isset($_POST['submit'])) to not display echo when script is open is not working

由 帅比萌擦擦* 提交于 2019-11-26 09:55:17
问题 I have a little problem with my if(isset($_POST[\'submit\'])) code. What I want is some echos and a table to not appear when the script is open but I do want it to show when the submit button for the form has been clicked. The problem is though that when I include the if(isset($_POST[\'submit\'])) function, when I click on the submit button it does not display the echos and the table at all. Why is this and can you help me out with this issue please. Below is the code: <!DOCTYPE html PUBLIC \

What&#39;s the difference between &#39;isset()&#39; and &#39;!empty()&#39; in PHP?

由 狂风中的少年 提交于 2019-11-26 04:26:10
问题 I don\'t understand the difference between isset() and !empty() . Because if a variable has been set, isn\'t it the same as not being empty? 回答1: ISSET checks the variable to see if it has been set. In other words, it checks to see if the variable is any value except NULL or not assigned a value. ISSET returns TRUE if the variable exists and has a value other than NULL. That means variables assigned a "", 0, "0", or FALSE are set, and therefore are TRUE for ISSET . EMPTY checks to see if a

Delete multiple rows by selecting checkboxes using PHP

由 回眸只為那壹抹淺笑 提交于 2019-11-26 04:25:44
问题 I want to delete multiple rows from MYSQL database. I have created this delete.php file to select various links and delete them using checkboxes. <html> <head> <title>Links Page</title> </head> <body> <h2>Choose and delete selected links.</h2> <?php $dbc = mysqli_connect(\'localhost\',\'root\',\'admin\',\'sample\') or die(\'Error connecting to MySQL server\'); $query = \"select * from links ORDER BY link_id\"; $result = mysqli_query($dbc,$query) or die(\'Error querying database\'); $count

Best way to test for a variable&#39;s existence in PHP; isset() is clearly broken

由 ▼魔方 西西 提交于 2019-11-26 03:03:53
问题 From the isset() docs: isset() will return FALSE if testing a variable that has been set to NULL. Basically, isset() doesn\'t check for whether the variable is set at all, but whether it\'s set to anything but NULL . Given that, what\'s the best way to actually check for the existence of a variable? I tried something like: if(isset($v) || @is_null($v)) (the @ is necessary to avoid the warning when $v is not set) but is_null() has a similar problem to isset() : it returns TRUE on unset

JavaScript isset() equivalent

由 为君一笑 提交于 2019-11-26 02:26:45
问题 In PHP you can do if(isset($array[\'foo\'])) { ... } . In JavaScript you often use if(array.foo) { ... } to do the same, but this is not exactly the same statement. The condition will also evaluate to false if array.foo does exists but is false or 0 (and probably other values as well). What is the perfect equivalent of PHP\'s isset in JavaScript? In a broader sense, a general, complete guide on JavaScript\'s handling of variables that don\'t exist, variables without a value, etc. would be

If isset $_POST

由 北城以北 提交于 2019-11-26 02:17:29
问题 I have a form on one page that submits to another page. There, it checks if the input mail is filled. If so then do something and if it is not filled, do something else. I don\'t understand why it always says that it is set, even if I send an empty form. What is missing or wrong? step2.php: <form name=\"new user\" method=\"post\" action=\"step2_check.php\"> <input type=\"text\" name=\"mail\"/> <br /> <input type=\"password\" name=\"password\"/><br /> <input type=\"submit\" value=\"continue\"/

Search Form with One or More (Multiple) Parameters

由 六眼飞鱼酱① 提交于 2019-11-25 22:38:27
问题 I\'ve gotten the basics down, where I\'ve created two files, the search form where a user inputs search parameters, and the results file that cranks out inputted items. For the sake of simplicity we\'ll designate the search form file as search.php and the results page as results.php. EDIT: Cleaned up tab etiquette for smoother reading. search.php <?php if(!empty($_POST[\'id\']) && isset($_POST[\'id\'])) { header(\"Location: ?m=search.results&id=\".$_POST[\'id\'].\"\"); } elseif(!empty($_POST[
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