Julia 中的反转数组元素——reverse()、reverse!() 和 reverseind() 方法
reverse()
是 julia 中的一个内置函数,用于将指定的向量v从开始反转到停止。
Syntax:
reverse(v, start, stop)
or
reverse(A; dims::Integer)
Parameters:
- v: Specified vector.
- start: Specified starting value.
- stop: Specified stopping value.
- A: Specified array.
- dims::Integer: Specified dimensions.
Returns: It returns a reversed copy of the vector.
示例 1:
# Julia program to illustrate
# the use of reverse() method
# Getting the reversed copy of
# the specified vector.
A = Vector(2:8)
println(reverse(A))
println(reverse(A, 3, 6))
println(reverse(A, 7, 4))
输出:
[8, 7, 6, 5, 4, 3, 2]
[2, 3, 7, 6, 5, 4, 8]
[2, 3, 4, 5, 6, 7, 8]
示例 2:
# Julia program to illustrate
# the use of reverse() method
# Getting reversed array in
# the specified dimension
A = [5 10; 15 20]
println(reverse(A, dims = 1))
println(reverse(A, dims = 2))
输出:
逆转!()
reverse!()
是 julia 中的内置函数,它是 reverse()函数的就地版本。
Syntax:
reverse!(v, start, stop)
Parameters:
- v: Specified vector.
- start: Specified starting value.
- stop: Specified stopping value.
Returns: It returns a reversed copy of the vector.
例子:
# Julia program to illustrate
# the use of reverse !() method
# Getting the reversed copy of
# the specified vector.
A = Vector(2:8)
println(reverse !(A))
println(reverse !(A, 3, 6))
输出:
[8, 7, 6, 5, 4, 3, 2]
[8, 7, 3, 4, 5, 6, 2]
逆向
reverseind()
是 julia 中的内置函数,用于返回 v 中的相应索引,因此 v[reverseind(v, i)] == reverse(v)[i],其中 i 是给定索引。
Syntax:
reverseind(v, i)
Parameters:
- v: Specified string.
- i: Specified index.
Returns: It returns the corresponding index in v so that v[reverseind(v, i)] == reverse(v)[i].
例子:
# Julia program to illustrate
# the use of reverseind() method
# Getting the corresponding index in v
# so that v[reverseind(v, i)] == reverse(v)[i]
V = reverse("Geeks")
for i in 1:length(r)
print(V[reverseind("Geeks", i)])
end
输出: