Why Does the Double Bitwise NOT Operator (~~) in JavaScript Behave Differently for Negative Numbers?

What's the Purpose of the Double Bitwise NOT Operator (~~) in JavaScript?

In JavaScript, the "double tilde" (~~) operator is a double Bitwise NOT operator. It serves as a faster alternative to the Math.floor() method for positive numbers.

When applied to a positive number, ~~ performs a bitwise NOT operation twice. This results in effectively truncating the fractional part of the number, similar to Math.floor().

For example, ~~5.8 would return 5, just like Math.floor(5.8).

However, ~~ behaves differently with negative numbers. Instead of rounding down, it chops off the fractional part, essentially returning the integer towards zero.

For instance, ~~-5.8 would return -5, unlike Math.floor(-5.8) which rounds down to -6.

It's important to note that ~~ is not intended for use with negative numbers and its behavior for negative inputs can vary across different JavaScript environments. Therefore, when working with negative values, it's recommended to explicitly use Math.floor() or other appropriate methods for rounding.

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