php - 比较变量 PHP

Question

如何比较两个变量字符串，会是这样吗:

$myVar = "hello";
if ($myVar == "hello") {
//do code
}

并检查 url 中是否存在 $_GET[] 变量，它会像这样"

$myVars = $_GET['param'];
if ($myVars == NULL) {
//do code
}

Answer 1

$myVar = "hello";
if ($myVar == "hello") {
    //do code
}

$myVar = $_GET['param'];
if (isset($myVar)) {
    //IF THE VARIABLE IS SET do code
}


if (!isset($myVar)) {
    //IF THE VARIABLE IS NOT SET do code
}

供您引用，当我第一次启动 PHP 时，这件事让我苦恼了好几天:

$_GET["var1"] // these are set from the header location so www.site.com/?var1=something
$_POST["var1"] //these are sent by forms from other pages to the php page