StructMap

Note:

You can also set the maximum thread count in ColdFusion Administrator. Click Server Settings > Settings and specify the number of threads in Default Maximum Thread Count For Parallel Functions.

Description

Iterates over every entry of the Struct and calls the closure function to work on the key value pair of the struct. The returned value will be set for the same key in a new struct and the new struct will be returned.

Returns

Struct

Syntax

structMap(struct, function(key, value [,struct]){} [, parallel] [, maxThreadCount])

History

ColdFusion (2021 release): Introduced the following parameters:

parallel
maxThreadCount

ColdFusion 11: Added this function.

Parameters

Parameter	Req/Opt	Description
struct	Required	The input struct.
function	Required	Closure or a function reference that will be called for each of the iteration. The arguments passed to the callback are key: key for the current iteration value: the value for the current iteration struct: a reference of the original struct
parallel	Optional	True if you want to enable parallel programming.
maxThreadCount	Optional	The number of threads the function can execute. The number of threads must be between 1-50. If the value exceeds 50, there is an exception.

Example

<cfscript>
       myStruct=StructNew();
       myStruct = {a:1,b=2,c=3,d=4,e=5,f=6};
       WriteOutput("The input struct is:");
       WriteDump(myStruct);
       myMap=StructMap(myStruct,function(key,value){
             return #value#^2;// Return squared values of struct members
       });
       WriteOutput("The output struct is:");
       WriteDump(myMap); // Writes a new struct with squared values
</cfscript>

Output

Using member function

<cfscript>
       myStruct = {a:1,b=2,c=3,d=4,e=5,f=6};
       myNewMap=myStruct.map(function(key,value){
             return value*5;
       });
       WriteDump(myNewMap);
</cfscript>

Using parallelization

<cfscript> 
mystruct= Structnew("ordered"); 
for(i=1;i<=10000;i++){ 
mystruct.insert("key#i#","val#i#") 
 
} 
function callback(key,val){ 
return val = val & "struct123" 
 } 
   
 
 s = mystruct.map(callback,false) 
 writeoutput(s['key1'] & "<br>") 
 s = mystruct.map(callback,true); 
 writeoutput(s['key1']  & "<br>") 
  s= mystruct.map(callback,true,10) 
 writeoutput(s['key1']  & "<br>") 
  s= structmap(struct=mystruct,callback=callback,parallel=true,maxthreadcount=20) 
 writeoutput(s['key1']  & "<br>") 
 s = structmap(struct=mystruct,callback=callback,parallel=true,maxthreadcount=40) 
 writeoutput(s['key1']  & "<br>") 
 try { 
 structmap(struct=mystruct,callback=callback,parallel=true,maxthreadcount=-20) 
 } 
 catch(any e){ 
  writeoutput("<br>Type: " & e.type & " Message:" &  e.message ) 
} 
 try{ 
 structmap(struct=mystruct,callback=callback,parallel=true,maxthreadcount=200) 
 } 
 catch(any e){ 
  writeoutput("<br>Type: " & e.type & " Message:" &  e.message ) 
} 
  
</cfscript>

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