javascript正则表达式检查IP地址 [英] javascript regular expression to check for IP addresses

问题描述

我有几个IP地址，如：

I have several ip addresses like:

1. 115.42.150.37


2. 115.42.150.38


3. 115.42.150.50

1. 115.42.150.37
2. 115.42.150.38
3. 115.42.150.50

如果我想搜索所有3个ip地址，我应该写什么类型的正则表达式？例如，如果我 115.42.150。* （我将能够搜索所有3个IP地址）

What type of regular expression should I write if I want to search for the all the 3 ip addresses? Eg, if I do 115.42.150.* (I will be able to search for all 3 ip addresses)

我现在可以做的是： / [0-9] {1-3} \。[0-9] {1-3} \。[0-9] {1 -3} \。[0-9] {1-3} / 但它似乎无法正常工作。

What I can do now is something like: /[0-9]{1-3}\.[0-9]{1-3}\.[0-9]{1-3}\.[0-9]{1-3}/ but it can't seems to work well.

谢谢。

推荐答案

你已经有的正则表达式有几个问题：

The regex you've got already has several problems:

首先，它包含点。在正则表达式中，点表示匹配任何字符，您只需匹配实际点。为此，你需要逃避它，所以在点前放一个反斜杠。

Firstly, it contains dots. In regex, a dot means "match any character", where you need to match just an actual dot. For this, you need to escape it, so put a back-slash in front of the dots.

其次，但你匹配每个部分的任何三位数。这意味着您将匹配0到999之间的任何数字，这显然包含许多无效的IP地址编号。

Secondly, but you're matching any three digits in each section. This means you'll match any number between 0 and 999, which obviously contains a lot of invalid IP address numbers.

这可以通过使数字匹配更复杂来解决;在这个网站上有其他答案解释如何做到这一点，但坦率地说，这是不值得的 - 在我看来，你最好用点分割字符串，然后只是将四个块验证为数字整数范围 - 即：

This can be solved by making the number matching more complex; there are other answers on this site which explain how to do that, but frankly it's not worth the effort -- in my opinion, you'd be much better off splitting the string by the dots, and then just validating the four blocks as numeric integer ranges -- ie:

if(block > 0 && block <256) {....}

希望有所帮助。

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