🔰double tilde (~~)

JS ⟩ statement ⟩ expression ⟩ operator ⟩ double tilde (~~)

nearest integer towards 0.

// ⭐️ ~~(x) : nearest integer towards 0
~~(-5.5)        // -5
~~( 5.5)        //  5

+undefined      // ⭐️ NaN
~~undefined     // ⭐️ 0

// similar operators
!!x        // any -> bool
+x         // any -> number

💡 it's not really an operator, it's just ~~x === ~(~x).

👉 bitwise not (~) | 🌟 2's complement

👥 相關

• ⚖️ (~~) vs. Math.trunc()

• ➕ bitwise operator ⟩ bitwise not (~) - invert bits.

• ➕ unary arithmetic operator ⟩ unary plus (+)

• ➕ unary logical operator ⟩ logical not (!)

💈範例

"~~" vs. Math.trunc()

注意：使用 JSON.stringify() 將函數轉換成字串時，會轉成 "undefined"❗️

📗 參考

• CodeWars ⟩ Adding Big Numbers

📘 手冊

• Bitwise NOT (~)

• Math.trunc() - same as ~~ (with wider range)

🗣 討論

• SOF ⟩ What does ~~ ("double tilde") do in Javascript?