checkbounds(::Type{Bool}, ::Integer, index)
checkbounds(::Type{Bool}, dimlength::Integer, index)
Return a Bool
describing if the given index is within the bounds of the given
dimension length. Custom types that would like to behave as indices for all
arrays can extend this method in order to provide a specialized bounds checking
implementation.
Examples
julia> arr = [1, 2, 3, 4, 5];
julia> checkbounds(arr, 3)
3
julia> checkbounds(arr, 6)
ERROR: BoundsError: attempt to access 5-element Vector{Int64} at index [6]
In the above example, the checkbounds
function is used to verify if the specified index is within the bounds of the array. If the index is valid, it returns the index itself. However, if the index is out of bounds, it throws a BoundsError
with an appropriate error message.
Common mistake example:
julia> arr = [10, 20, 30];
julia> checkbounds(arr, 0)
ERROR: BoundsError: attempt to access 3-element Vector{Int64} at index [0]
In this example, the index provided is 0, which is not a valid index for an array in Julia. Remember that Julia uses 1-based indexing, so the valid indices for an array of length n
are from 1 to n
. Always ensure that the indexes passed to checkbounds
are within the correct range to avoid such errors.
See Also
User Contributed Notes
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