변수 종류 확인 (타입 체크, type check)

 

Equals Operator ( == ) vs Strict Equals Operator ( === )

 

	class Ca {
		mA = 0;
	}

	let v1 = 123;
	let sb1 = Symbol("SymbolSb1");
	let ca = new Ca();

	console.log(typeof v1 === 'number'); //true
	
	console.log(typeof ca); //object
	console.log(typeof ca == 'Ca'); //false
	console.log(typeof ca == 'object'); //true

	console.log(ca instanceof Ca); //true