files/zh-cn/web/javascript/reference/operators/right_shift_assignment/index.md


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---
title: 右移赋值 (>>=)
slug: Web/JavaScript/Reference/Operators/Right_shift_assignment
tags:
  - Assignment operator
  - JavaScript
  - Language feature
  - Operator
  - Reference
browser-compat: javascript.operators.right_shift_assignment
---
{{jsSidebar("Operators")}}

右移赋值运算符 (`>>=`) 将变量向右移动指定数量的位，并将结果赋值给变量。

{{EmbedInteractiveExample("pages/js/expressions-right-shift-assignment.html")}}

## 语法

```js
x >>= y // x = x >> y
```

## 例子

### 使用右移赋值运算符

```js
let a = 5; //   (00000000000000000000000000000101)
a >>= 2;   // 1 (00000000000000000000000000000001)

let b = -5; //  (-00000000000000000000000000000101)
b >>= 2;  // -2 (-00000000000000000000000000000010)
```

## 规范

{{Specifications}}

## 浏览器兼容性

{{Compat}}

## 参考

- [JS 指南中的赋值运算符](/zh-CN/docs/Web/JavaScript/Guide/Expressions_and_Operators#assignment)
- [右移运算符](/zh-CN/docs/Web/JavaScript/Reference/Operators/Right_shift)