> For the complete documentation index, see [llms.txt](https://jaywin.gitbook.io/leetcode/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://jaywin.gitbook.io/leetcode/solutions/0007-reverse-integer.md).

# 0007. Reverse Integer

<https://leetcode.com/problems/reverse-integer>

## Description

Given a signed 32-bit integer `x`, return `x` *with its digits reversed*. If reversing `x` causes the value to go outside the signed 32-bit integer range `[-231, 231 - 1]`, then return `0`.

**Assume the environment does not allow you to store 64-bit integers (signed or unsigned).**

**Example 1:**

```
**Input:** x = 123
**Output:** 321
```

**Example 2:**

```
**Input:** x = -123
**Output:** -321
```

**Example 3:**

```
**Input:** x = 120
**Output:** 21
```

**Example 4:**

```
**Input:** x = 0
**Output:** 0
```

**Constraints:**

* `-231 <= x <= 231 - 1`

## ac

```java
```