为什么 JavaScript 位运算左移会输出负数?

[rabbbit]

Python

3 << 29
# 1610612736
3 << 30
# 3221225472L

JavaScript

3 << 29
// 1610612736
3 << 30
// -1073741824

为什么 JavaScript 位运算左移会输出负数?

[geelaw]

搜索 javascript left shift

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators

Bitwise operators treat their operands as a sequence of 32 bits (zeroes and ones).

...

Bitwise operators perform their operations on such binary representations, but they return standard JavaScript numerical values.

...

Signed 32-bit integers

The operands of all bitwise operators are converted to signed 32-bit integers in two's complement format.

[mooncakejs]

应该是 python 为什么不是负数吧

[MiffyLiye]

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Bitwise_Operators

[MiffyLiye]

而 Python 里整数是无限长的