我需要删除列表中的最后一个元素.我在shell中运行此代码.
Erlang R16B03(erts-5.10.4)[source] [64-bit] [smp:4:4] [async-threads:10] [kernel-poll:false]
erl + pc unicode
ColumnListWithCommas = [<<"username">>,<<",">>,<<"password">>,<<",">>, <<"created_at">>,<<",">>,<<"id">>,<<",">>,<<"email_hash">>, <<",">>,<<"status">>,<<",">>,<<"mess_count">>,<<",">>]. lists:droplast(ColumnListWithCommas). ** exception error: undefined function lists:droplast/1
couchemar.. 6
没有列表:Erlang R16B03中的droplast/1.你需要Erlang 17.0
你可以做:
1> A = [1, 2, 3, 4]. 2> lists:reverse(tl(lists:reverse(A))). [1,2,3] Or 3> {L, _} = lists:split(length(A) - 1, A).
还有一种方法.您可以从Erlang源代码中实现它非常简单
没有列表:Erlang R16B03中的droplast/1.你需要Erlang 17.0
你可以做:
1> A = [1, 2, 3, 4]. 2> lists:reverse(tl(lists:reverse(A))). [1,2,3] Or 3> {L, _} = lists:split(length(A) - 1, A).
还有一种方法.您可以从Erlang源代码中实现它非常简单