从freemarker的列表中获取子列表 [英] Get sub list from a list in freemarker

问题描述

我在免费标记中有一个列表，如下所示:

I have a list in free marker as below:

 <#assign listVar = ["v1", "v2", "v3", "v4" ] />

从上面的列表中，我只希望子列表为v1和v2.

From the above list I just want the sub list as v1 and v2.

我一直在徘徊以获取免费标记中的子列表.但是找不到.

I have been wandering to get the sub list in free marker. But couldn't managed to find.

任何帮助将不胜感激.

推荐答案

如果您真的想基于索引制作该切片:

If you really want to make that slice based on indexes:

<#assign listVar = ["v1", "v2", "v3", "v4" ] />
<#assign sublistVar = listVar[0..1] />

请参见 Freemarker序列切片.

但是请注意，如果索引超出范围，它将以错误停止.根据您需要的用途，可能要改用?chunk(2).

But beware, it will stop with error if the index is out of range. Depending on what you need this for, you may want to use ?chunk(2) instead.

更新:为避免出现索引越界错误，在FreeMarker 2.3.21中，您可以发出listVar[0..*2]，它将切出2个项目，如果可用空间较小，则减少两个项目. (也可以使用专用端切片:listVar[0..<2])

Update: As of avoiding index-out-of-bounds error, in FreeMarker 2.3.21 you can issue listVar[0..*2], which will slice out 2 items, or less if there's less available. (Also exclusive-end slicing can come handy: listVar[0..<2])

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