tuple_first_ntuple_first_nTupleFirstNTupleFirstNtuple_first_n (算子)

名称

tuple_first_ntuple_first_nTupleFirstNTupleFirstNtuple_first_n — 选择元组中索引 “n” 之前的第一个元素。

签名

描述

tuple_first_ntuple_first_nTupleFirstNTupleFirstNTupleFirstNtuple_first_n selects the first elements of TupleTupleTupleTupletupletuple up to the index IndexIndexIndexIndexindexindex and returns them in SelectedSelectedSelectedSelectedselectedselected. Indices of tuple elements start at 0, that means, the first tuple element has got the index 0. In total, IndexIndexIndexIndexindexindex+1 elements are returned.

IndexIndexIndexIndexindexindex must contain a single integer value (or a floating point number that represents an integer value without fraction).

例外：空输入元组

If TupleTupleTupleTupletupletuple is empty, an exception is raised.

HDevelop 内联操作

HDevelop provides an in-line operation for tuple_first_ntuple_first_nTupleFirstNTupleFirstNTupleFirstNtuple_first_n, which can be used in an expression in the following syntax:

Selected := firstn(Tuple, Index)

执行信息

• 多线程类型：独立（即使使用独占算子也能并行运行）。
• 多线程作用域：全局（可从任何线程调用）。
• 未采用并行化处理。

参数

替代

tuple_last_ntuple_last_nTupleLastNTupleLastNTupleLastNtuple_last_n, tuple_selecttuple_selectTupleSelectTupleSelectTupleSelecttuple_select, tuple_str_bit_selecttuple_str_bit_selectTupleStrBitSelectTupleStrBitSelectTupleStrBitSelecttuple_str_bit_select, tuple_concattuple_concatTupleConcatTupleConcatTupleConcattuple_concat, tuple_select_masktuple_select_maskTupleSelectMaskTupleSelectMaskTupleSelectMasktuple_select_mask

另见

tuple_removetuple_removeTupleRemoveTupleRemoveTupleRemovetuple_remove

模块

基础