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@Katsu8998(Katsu 8998)

Entityがnullかどうかを知る

Posted at

背景

javaの資材を修正した際に、作成されたentityListがnullかどうかで条件分岐した箇所があった。そこで自分は、CollectionとEntityをごっちゃにして考え、null判定をするためにメソッドを理解するのに時間を要した。そこで、メモとしてここに書き留めておく

EntityがNullかどうか判定する

"isNull", "nonNull","==null", "!=null"の4つ。
直観的にわかりやすいのは"isNull", "nonNull"かと思う

Listの中身がnullかどうか

"isEmpty()","list.size()==0"

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