go - 如何知道一个范围是否为空？

Question

如果我的范围为空，如何有条件地显示其他内容？

{{range .Users}}
...
{{end}}

如果范围为空，我想显示不同的 HTML 块。

Answer 1

使用{{range pipeline}} T1 {{else}} T0 {{end}}：

{{range pipeline}} T1 {{else}} T0 {{end}}
        The value of the pipeline must be an array, slice, map, or channel.
        If the value of the pipeline has length zero, dot is unaffected and
        T0 is executed; otherwise, dot is set to the successive elements
        of the array, slice, or map and T1 is executed.

例子：

{{range .Users}}
...
{{else}}
<p>No users</p>
{{end}}