コンストラクタ内でthisを使って他のコンストラクタを呼び出す場合、最初の行でなければなりません。 The sole time it is admittedly demanded is when you have a parameter to a method with the identical name like a member variable. Ways to detect the change in DIV's dimension ? The change in a div's dimension could be detected making use of two methods: Approach 1: https://thisav31087.ageeksblog.com/31224444/the-2-minute-rule-for-thisav