はじめに
phpを使う上でよくemptyやis_null、issetを使うが、完全に条件を覚えていないので簡単に見返せるよう、自分用に書く。
empty
emptyは厳しい
bool | |
---|---|
$checkVal=1 | false |
$checkVal='1' | false |
$checkVal=0 | true |
$checkVal='0' | true |
$checkVal=[] | true |
$checkVal=[0] | false |
$checkVal | true |
$checkVal='' | true |
$checkVal=null | true |
is_null
is_nullはゆるい
bool | |
---|---|
$checkVal=1 | false |
$checkVal='1' | false |
$checkVal=0 | false |
$checkVal='0' | false |
$checkVal=[] | false |
$checkVal=[0] | false |
$checkVal | true |
$checkVal='' | false |
$checkVal=null | true |
if
ifは厳しい
bool | |
---|---|
$checkVal=1 | true |
$checkVal='1' | true |
$checkVal=0 | false |
$checkVal='0' | false |
$checkVal=[] | false |
$checkVal=[0] | true |
$checkVal | false |
$checkVal='' | false |
$checkVal=null | false |
isset
issetはゆるい
bool | |
---|---|
$checkVal=1 | true |
$checkVal='1' | true |
$checkVal=0 | true |
$checkVal='0' | true |
$checkVal=[] | true |
$checkVal=[0] | true |
$checkVal | false |
$checkVal='' | true |
$checkVal=null | false |
総評
isがついてたらゆるい
empty | is_null | if | isset | |
---|---|---|---|---|
$checkVal=1 | false | false | true | true |
$checkVal='1' | false | false | true | true |
$checkVal=0 | true | false | false | true |
$checkVal='0' | true | false | false | true |
$checkVal=[] | true | false | false | true |
$checkVal=[0] | false | false | true | true |
$checkVal | true | true | false | false |
$checkVal='' | true | false | false | true |
$checkVal=null | true | true | false | false |