coacoapods中的podfile介紹；如何指定版本号(内容來自官方英文blog)

一個複雜的podfile:

Besides no version, or a specific one, it is also possible to use logical operators:

<code>'&gt; 0.1'</code> Any version higher than 0.1 0.1以上

<code>'&gt;= 0.1'</code> Version 0.1 and any higher version 0.1以上，包括0.1

<code>'&lt; 0.1'</code> Any version lower than 0.1 0.1以下

<code>'&lt;= 0.1'</code> Version 0.1 and any lower version 0.1以下，包括0.1

In addition to the logic operators CocoaPods has an optimisic operator <code>~&gt;</code>:

<code>'~&gt; 0.1.2'</code> Version 0.1.2 and the versions up to 0.2, not including 0.2 and higher 0.2以下(不含0.2)，0.1.2以上（含0.1.2）

<code>'~&gt; 0.1'</code> Version 0.1 and the versions up to 1.0, not including 1.0 and higher 1.0以下(不含1.0)，0.1以上（含0.1）

<code>'~&gt; 0'</code> Version 0 and higher, this is basically the same as not having it. 0和以上，等于沒有此限制