Question

我试图避免未定义的索引。我也使用了isset但是我无法获得理想的结果。

<body>

    <FORM NAME ="form1" METHOD ="POST" ACTION = "test.php">

<INPUT NAME = "search" size="74">
<INPUT TYPE = "Submit" Name = "SearchButton" VALUE = "Search">
</FORM> 

<?php  
    $search =  isset($_POST['search']);
    //$search = $_POST['search'];
if (!isset($_GET[$search])) {
    // category isn't set
    echo 'not set';

} 
 else {

    echo 'set';
}
?>

Answer 1

我想你想要

$search =  isset($_POST['search']) ? $_POST['search']  : 'some default';      
$search =  isset($_GET['search']) ? $_GET['search']  : 'some default';

Answer 2

当你执行$ _GET [$ search]时，这将评估为$ _GET [0]或$ _GET [1]，具体取决于参数'search'是否设置为post变量。我想你需要像

这样的东西

if( isset($_POST['search']) ) {
  //do something with the variable
}

在PHP中避免未定义的索引

2 个答案: