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Ben Myhre
28,726 PointsIsn't "A two-dimensional array is an array of objects." TRUE?
It says it is false, and I get where they are going. A two dimensional array is an array of arrays, BUT a js array IS a javascript object, right? So a two dimensional array, really is an array of objects... making the answer, technically, TRUE... or that is how I read it.
2 Answers
Iain Diamond
29,379 PointsPerhaps, a graphical example might help:
1D array - position is denoted by x
1234567890
2D array, position is denoted by x, y
1234567890
1234567890
1234567890
1234567890
1234567890
1234567890
1234567890
1234567890
iain
Colin Marshall
32,861 PointsI think you missed his point. An array is an object in JavaScript, so since a two dimensional array is an "array of arrays," it is technically also an array of objects.
Iain Diamond
29,379 PointsThinking logically, this obviously is false:
- A 1D array is a list of objects.
- A 2D array is an array of arrays.
- However, an array is also an object.
- Therefore, a 2D array is an array of objects.
- Ergo, a 2D array is a 1D array.
Alternatively,
- A 1D array is a list of objects.
- A 2D array is an array of arrays.
- Or a 2D array is an array of a list of objects.
- Also, a list of objects is not the same as a simple object.
- Therefore a 2D array is not the same as a 1D array.
iain
Colin Marshall
32,861 PointsI see what you are getting at, but Array - Javascript | MDN says differently about arrays.
The JavaScript Array global object is a constructor for arrays, which are high-level, list-like objects.
To me, a "list-like object" is not the same thing as a "list of objects."
Ben Myhre
28,726 PointsI see it differently and I think the console does too.
Iain Diamond
29,379 PointsApparently, not all objects are equal.
> var a = [1,2,3,4,5]
undefined
> typeof(a)
'object'
> typeof(a[0])
'number'
> typeof(a[0][0])
'undefined'
> b=[a,a]
[ [ 1, 2, 3, 4, 5 ], [ 1, 2, 3, 4, 5 ] ]
> typeof(b)
'object'
> typeof(b[0])
'object'
> typeof(b[0][0])
'number'
Colin Marshall
32,861 PointsColin Marshall
32,861 PointsI agree with your reasoning here. Maybe Dave McFarland can step in and explain this one for us.