MACROMEDIA ColdFusion MX, Develop Manual, Page: 107 / 860

Basic array techniques 107
The best way to understand an asymmetrical array is by looking at it. The following example
creates an asymmetric, multidimensional array and the
cfdump
tag displays the resulting array
structure. Several array elements do not yet contain data.
<cfset myarray=ArrayNew(1)>
<cfset myotherarray=ArrayNew(2)>
<cfset biggerarray=ArrayNew(3)>
<cfset biggerarray[1][1][1]=myarray>
<cfset biggerarray[1][1][1][10]=3>
<cfset biggerarray[2][1][1]=myotherarray>
<cfset biggerarray[2][1][1][4][2]="five deep">
<cfset biggestarray=ArrayNew(3)>
<cfset biggestarray[3][1][1]=biggerarray>
<cfset biggestarray[3][1][1][2][3][1]="This is complex">
<cfset myarray[3]="Can you see me">
<cfdump var=#biggestarray#> <br>
<cfdump var=#myarray#>
Note: The
cfdump
tag displays the entire contents of an array. It is an excellent tool for debugging
arrays and array-handling code.
Reviewing the code
The following table describes the code:
Code Description
<cfset myarray=ArrayNew(1)>
<cfset myotherarray=ArrayNew(2)>
<cfset biggerarray=ArrayNew(3)>
Create three empty arrays, a 1D array, a 2D array, and a 3D
array.
<cfset
biggerarray[1][1][1]=myarray>
<cfset biggerarray[1][1][1][10]=3>
Make element [1][1][1] of the 3D biggerarray array be a copy
of the 1D array. Assign 3 to the [1][1][1][10] element of the
resulting array.
The biggerarray array is now asymmetric. For example, it
does not have a [1][1][2][1] element.
<cfset biggerarray[2][1][1]=
myotherarray>
<cfset biggerarray[2][1][1][4][2]=
"five deep">
Make element [2][1][1] of the 3D array be the 2D array, and
assign the [2][1][1][4][2] element the value "five deep".
The biggerarray array is now even more asymmetric.
<cfset biggestarray=ArrayNew(3)>
<cfset biggestarray[3][1][1]
=biggerarray>
<cfset
biggestarray[3][1][1][2][3][1]
="This is complex">
Create a second 3D array. Make the [3][1][1] element of this
array be a copy of the bigerarray array, and assign element
[3][1][1][2][3][1].
The resulting array is very complex and asymmetric.
<cfset myarray[3]="Can you see
me">
Assign a value to element [3] of myarray.
<cfdump var=#biggestarray#><br>
<cfdump var=#myarray#>
Use
cfdump
to view the structure of biggestarray and
myarray.
Notice that the "Can you see me" entry appears in myarray,
but not in biggestarray, because biggestarray has a copy of
the original myarray values and is not affected by the change
to myarray.