如何检查一个字符串只包含数字和小数点?

For example I want to check that my when I split my string that the first part only contains numbers and decimal points.

例如，我想检查一下，当我把第一部分的字符串分开时，它只包含数字和小数点。

I have done the following

我已经做了以下的工作

String[] s1 = {"0.12.13.14-00000001-00000", "0.12.13.14-00000002-00000"};

        String[] parts_s1 = s1.split("-");
        System.out.println(parts_s1[0]);
        if(parts_s1[0].matches("[0-9]")

But thats only checking for numbers and not decimals. How can I also check for decimals in this? For example I want to check for 0.12.13.14 that it works and something like 0.12.13.14x will not work.

但那只是检查数字而不是小数。如何检查小数呢?例如，我要检查0。12.13。14是否有效，0。12.13。14x是否有效。

3 个解决方案

#1

Add the dot character in the regex as follows:

在regex中添加如下点字符:

if(parts_s1[0].matches("[0-9.]*")) {     // match a string containing digits or dots

The * is to allow multiple digits/decimal points.

*是允许多个数字/小数点。

In case at least one digit/decimal point is required, replace * with + for one or more occurrences.

如果至少需要一个数字/小数点，可以用+替换一个或多个数字。

EDIT:

编辑:

In case the regex needs to match (positive) decimal numbers (not just arbitrary sequences of digits and decimal points), a better pattern would be:

如果regex需要匹配(正的)十进制数(而不仅仅是任意的数字和小数点序列)，那么更好的模式应该是:

if(parts_s1[0].matches("\\d*\\.?\\d+")) {    // match a decimal number

Note that \\d is equivalent to [0-9].

注意，\d等同于[0-9]。

#2

You can use this regex:

您可以使用这个regex:

\\d+(\\.\\d+)*

Code:

代码:

if(parts_s1[0].matches("\\d+(\\.\\d+)*") {...}

#3

You can simply add a dot to the list of allowed characters:

您只需在允许的字符列表中添加一个点:

if(parts_s1[0].matches("[.0-9]+")

This, however, would match strings that are composed entirely of dots, or have sequences of multiple dots.

然而，这将匹配完全由点组成的字符串，或具有多个点的序列。

#1