if($_POST['cropProfileData'] == undefined || $_POST['cropProfileData'] == null || $_POST['cropProfileData'] == 0) {
echo "NO process profile photo....";
}else{
echo "YES process profile photo....";
}
这个工作得很好-它告诉我数组是否为空。
问题是我只需要'echo "YES process profile photo…"。
我怎样才能得到上面IF语句的NOT ?我试过添加"!"'之后的if -例如:if!(和我已经尝试添加'!
是否有一种方法来获得这个语句的NOT -将节省我不得不包括else，这是毫无意义的代码。
thx
PS:这样做的原因是查看数组是否为空。
仅!empty( $_POST[ 'cropProfileData' ] )将涵盖所有这些情况(尽管undefined在PHP中不使用，除非它是某个常量)。
if( !empty( $_POST[ 'cropProfileData' ] ) ) {
echo "YES process profile photo....";
}
理论
否定表达式是这样的:
if (!($_POST['cropProfileData'] == undefined || $_POST['cropProfileData'] == null || $_POST['cropProfileData'] == 0)) {
根据De Morgan的说法，表达式也可以写成:
if ($_POST['cropProfileData'] != undefined && $_POST['cropProfileData'] != null && $_POST['cropProfileData'] != 0) {
要测试某物是否为undefined，应该使用isset()，例如:
$_POST['cropProfileData'] == undefined || $_POST['cropProfileData'] == null
应该写成:
!isset($_POST['cropProfileData'])
专门测试数组是否为空:
isset($_POST['cropProfileData']) && is_array($_POST['cropProfileData']) && count($_POST['cropProfileData'])
,或者更简单:
if (!empty($_POST['cropProfileData']) && is_array($_POST['cropProfileData'])) {
<?php
/*
if($a == undefined || $b == null || $c == 0) {
echo "NO process profile photo....";
}else{
echo "YES process profile photo....";
}
*/
if($a != undefined && $b != null && $c != 0) {
echo "NO process profile photo....";
}else{
echo "YES process profile photo....";
}
?>
你只需要检查数组是否为空
if(!empty( $_POST[ 'cropProfileData' ] )){echo "YES process profile photo....";}