js 変数の型判別

primitive型

console.log(typeof 42);
// expected output: "number"

console.log(typeof 'blubber');
// expected output: "string"

console.log(typeof true);
// expected output: "boolean"

console.log(typeof undeclaredVariable);
// expected output: "undefined"

class

if(dog instanceof Animal){

}

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Related Notes

References

• https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/typeof
• https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Operators/instanceof

Tags

• #js