在 Julia 中获取数组的第一个元素 - first() 方法

first()是 julia 中的内置函数，用于返回指定可迭代集合的第一个元素。

Syntax: first(coll)

Parameters:

• coll: Specified iterable collection.

Returns: It returns the first element of the specified iterable collection.

示例 1：

# Julia program to illustrate 
# the use of first() method
   
# Getting the first element of 
# the specified iterable collection
# or 1D array
println(first(1:2:3))
println(first(5:10))
println(first([3, 5, 7, 9]))
println(first([2, 4, 6, 8]))

输出：

1
5
3
2

示例 2：

# Julia program to illustrate 
# the use of first() method
   
# Getting the first element of 
# the specified 2D and 3D array
println(first([3 5; 7 9]))
println(first(["a" "b"; "c" "d"]))
println(first(cat([1 2; 3 4], [5 6; 7 8], 
                  [2 2; 3 4], dims = 3)))
println(first(cat(["a" "b"; "c" "d"], 
                  ["e" "f"; "g" "h"], 
                  ["i" "j"; "k" "l"], dims = 3)))

输出：