coldfusion less cumbersome way to create four structures based on array modulus - coldfusion

Question

I have an array "varray" which needs to be split into four structures. The first of each four elements should be in structure 1, the second in structure 2, etc. I have some working code to do this, but it feels to me like there should be a less cumbersome way. Here is the code:
<cfset xord = StructNew()>
<cfset xsort = StructNew()>
<cfset xsel = StructNew()>
<cfset xmer = StructNew()>
<cfloop from = '1' to = "#ArrayLen(varray)#" index = 'i'>
<cfset fieldname = farray[i]> <!---farray previously defined --->
<cfset val = varray[i]> <!---varray previously defined --->
<cfset j = i%4>
<cfif j EQ 1>
<cfset xord[fieldname] = val>
<cfselseif j EQ 2>
<cfset xsort[fieldname]= val>
<cfelseif j EQ 3>
<cfset xsel[fieldname] = val>
<cfelseif j EQ 0>
<cfset xmer[fieldname] = val>
</cfif>
</cfloop>
Can anyone suggest a better way to do this?

Answer 1

It's been ages i did some CF, but a tag based approach by making use of local scope:
<cfset keys = ['xord', 'xsort', 'xsel', 'xmer'] />
<cfset farray = ['f1','f2','f3','f4','f5','f6','f7','f8']>
<cfset varray = ['v1','v2','v3','v4','v5','v6','v7','v8']>
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfset local[keys[i%4+1]][farray[i]] = varray[i]>
</cfloop>
<cfdump var="#xord#" />
<cfdump var="#xsort#" />
<cfdump var="#xsel#" />
<cfdump var="#xmer#" />
Now you have xord, xsort, xsel and xmer filled with the right key-value pairs within your local scope.

Answer 2

How about cfscript?
<cfscript>
function groupByOp(values, fieldnames) {
var ops = ['mer', 'ord', 'sort', 'sel'];
var byOp = {};
arrayEach(values, function (val, i) {
byOp["x#ops[i % 4 + 1]#"][fieldnames[i]] = val;
});
return byOp;
}
</cfscript>
This makes use of the fact that CF will automagically create structs when you mention a non-existing member.
Test:
<cfset v = ListToArray('1,2,3,4,5,6')>
<cfset f = ListToArray('a,b,c,d,e,f')>
<cfoutput>
<pre>#SerializeJSON(groupByOp(v, f))#</pre>
</cfoutput>
outputs
{
"xsel": {
"c": "3"
},
"xord": {
"e": "5",
"a": "1"
},
"xsort": {
"b": "2",
"f": "6"
},
"xmer": {
"d": "4"
}
}

Answer 3

(You didn't mention your version, so I don't know if you have access to newer functions like array each(). Keep in mind there's slicker options in newer versions)
Instead of creating separate variables, create a single structure containing the 4 variables, and an array of names. Then use the array and MOD to populate the substructures. Note, the example below creates the subsubstructures up front to ensure they always exist - even if the field/value arrays are empty or contain less than 4 elements.
TryCF.com Example
<cfset farray = ["A","B","C","D","E","F","G","Q","T"]>
<cfset varray = ["11","22","33","RR","55","NN","77","68","46"]>
<cfset data = {xOrd={},xSort={},xSel={},xMer={}}>
<cfset names = ["xOrd","xSort","xSel","xMer"]>
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfset fieldName = farray[i]>
<cfset fieldValue = varray[i]>
<cfset structName = names[i%4+1]>
<cfset data[structName][fieldName] = fieldValue>
</cfloop>
The substructures can be accessed through the parent, data.
<cfdump var="#data.xOrd#" label="data.xOrd">
<cfdump var="#data.xSort#" label="data.xSort">
<cfdump var="#data.xSel#" label="data.xSel">
<cfdump var="#data.xMer#" label="data.xMer">

Answer 4

Another couple of approaches.
I wouldn't necessarily say that these are better, but just different:
Requires field array length to match value array length
<cfset farray = ['field1','field2','field3','field4','field5']>
<cfset varray = ['apple','orange','pear','kiwi','pineapple']>
<cfset xord = {}>
<cfset xsort = {}>
<cfset xsel = {}>
<cfset xmer = {}>
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfset j =
((i%4 EQ 1) ? (StructInsert(xord,farray[i],varray[i])):
((i%4 EQ 2) ? (StructInsert(xsort,farray[i],varray[i])):
((i%4 EQ 3) ? (StructInsert(xsel,farray[i],varray[i])):
((i%4 EQ 0) ? (StructInsert(xmer,farray[i],varray[i])): 0))))>
</cfloop>
<cfdump var="#xord#" />
<cfdump var="#xsort#" />
<cfdump var="#xsel#" />
<cfdump var="#xmer#" />
OR:
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfswitch expression="#i%4#">
<cfcase value="0">
<cfset xmer[farray[i]] = varray[i]>
</cfcase>
<cfcase value="1">
<cfset xord[farray[i]] = varray[i]>
</cfcase>
<cfcase value="2">
<cfset xsort[farray[i]] = varray[i]>
</cfcase>
<cfcase value="3">
<cfset xsel[farray[i]] = varray[i]>
</cfcase>
</cfswitch>
</cfloop>
<cfdump var="#xord#" />
<cfdump var="#xsort#" />
<cfdump var="#xsel#" />
<cfdump var="#xmer#" />
Field array length does not have to match value array length
<cfset farray = ['field1','field2','field3','field4']>
<cfset varray = ['apple','orange','pear','kiwi','pineapple']>
<cfset xord = {}>
<cfset xsort = {}>
<cfset xsel = {}>
<cfset xmer = {}>
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfset j =
((i%4 EQ 1 AND ArrayIsDefined(farray,i)) ? (StructInsert(xord,farray[i],varray[i],true)) :
((i%4 EQ 2 AND ArrayIsDefined(farray,i)) ? (StructInsert(xsort,farray[i],varray[i],true)) :
((i%4 EQ 3 AND ArrayIsDefined(farray,i)) ? (StructInsert(xsel,farray[i],varray[i],true)) :
((i%4 EQ 0 AND ArrayIsDefined(farray,i)) ? (StructInsert(xmer,farray[i],varray[i],true)) : 0))))>
</cfloop>
<cfdump var="#xord#" />
<cfdump var="#xsort#" />
<cfdump var="#xsel#" />
<cfdump var="#xmer#" />
OR:
<cfloop from="1" to="#ArrayLen(varray)#" index="i">
<cfswitch expression="#i%4#">
<cfcase value="0">
<cfset (ArrayIsDefined(farray,i) ? (StructInsert(xmer,farray[i],varray[i],true)) : 0)>
</cfcase>
<cfcase value="1">
<cfset (ArrayIsDefined(farray,i) ? (StructInsert(xord,farray[i],varray[i],true)) : 0)>
</cfcase>
<cfcase value="2">
<cfset (ArrayIsDefined(farray,i) ? (StructInsert(xsort,farray[i],varray[i],true)) : 0)>
</cfcase>
<cfcase value="3">
<cfset (ArrayIsDefined(farray,i) ? (StructInsert(xsel,farray[i],varray[i],true)) : 0)>
</cfcase>
</cfswitch>
</cfloop>
<cfdump var="#xord#" />
<cfdump var="#xsort#" />
<cfdump var="#xsel#" />
<cfdump var="#xmer#" />