型を調べたい時：
console.log(typeof 5); // number
console.log(typeof null); //object と表示される
文字列を整数に変換して計算：10進数の5に、3を足す。
console.log(parseInt('5', 10) + 3);
More than 1 year has passed since last update.
Register as a new user and use Qiita more conveniently
- You get articles that match your needs
- You can efficiently read back useful information
- You can use dark theme