获取 Julia 中数组最后一个真值的索引 |数组 findlast() 方法
findlast()
是 julia 中的一个内置函数,用于返回指定数组中最后一个真值的索引或键。这里索引或键的值从 1 开始,即第一个元素的索引是 1,第二个元素的索引是 2,依此类推。
Syntax:
findlast(A)
or
findlast(predicate::Function, A)
Parameters:
- A: Specified array
- Predicate Function: Determines whether something is true or false based on the specified arguments
Returns: It returns the index or key of the last true value in the specified array.
示例 1:
# Julia program to illustrate
# the use of Array findlast() method
# Finding index of last true value from
# the 1D array A
A = [false, true, true, false]
println(findlast(A))
# Finding index of last true value from
# the 2D array B of size 2 * 2
B = [false false; true false]
println(findlast(B))
# Finding index of last true value from
# the 3D array C of size 2 * 2*2
C = cat([false false; true false],
[false true; true false],
[true false; true true], dims = 3)
println(findlast(C))
输出:
示例 2:
# Julia program to illustrate
# the use of Array findlast() method
# Finding index of last even value from
# the 1D array A
A = [1, 2, 5, 6]
println(findlast(iseven, A))
# Finding index of last even value from
# the 2D array B of size 2 * 2
B = [3 5; 6 7]
println(findlast(iseven, B))
# Finding index of last even value from
# the 3D array C of size 2 * 2*2
C = cat([1 2; 3 4], [5 6; 7 8],
[9 10; 11 12], dims = 3)
println(findlast(iseven, C))
输出: