StructFilter

Last updated on Apr 27, 2021 06:02:40 AM GMT | Also Applies to ColdFusion

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

Filters the key-value pairs in a struct.

Returns

Filtered struct.

Syntax

structFilter(struct,callback [, parallel] [, maxThreadCount])

History

ColdFusion (2021 release): Introduced the following parameters:

parallel
maxThreadCount

ColdFusion (2018 release): Introduced named parameters.

ColdFusion 10: Added this function.

Parameters

Parameter	Description
struct	Name of the struct object.
callback	Inline function executed for each element in the array. Returns true if the key value pair in the struct has to be included in the resultant struct.
parallel	(Boolean)- True if you want to enable parallel programming.
maxThreadCount	(Int) 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={CF1=4.5,CF2=6,CF3=7,CF4=8,CF5=9,CF6=10,CF7=11,CF8=2016};
       WriteOutput("The input, unfiltered struct is:");
       WriteDump(myStruct);
       myFilteredStruct=StructFilter(myStruct,function(key,value){
             return value>8; //Return only those values >8
       }
       );
       WriteOutput("The filtered struct is:");
       WriteDump(myFilteredStruct);//Display the filtered struct
</cfscript>

Output

Using member function

<cfscript>
       myStruct={CF1=4.5,CF2=6,CF3=7,CF4=8,CF5=9,CF6=10,CF7=11,CF8=2016};
       CFVersions=myStruct.filter(function(key,value){
             return value>8;
       });
       WriteDump(CFVersions);
</cfscript>

Using parallelization

<cfscript> 
 mystruct= Structnew("ordered"); 
 for(i=1;i<=10000;i++){ 
  mystruct.insert("key#i#","val#i#") 
 
 } 
 function callback(key,val){ 
  if(isObject(val)) 
   eturn false 
  else if(isSimplevalue(val) && key eq 'key889') 
  {  
   return true 
  } 
  else return false 
 } 
   
  
 writeoutput(mystruct.filter(callback,false)[ 
 "key889"]) 
  
 writeoutput(mystruct.filter(callback,true)[ 
 "key889"]); 
  
 writeoutput(mystruct.filter(callback,true,10)[ 
 "key889"]) 
  
 writeoutput(structfilter(struct=mystruct,callback=callback,parallel=true,maxthreadcount=20)[ 
 "key889"]) 
  
 writeoutput(structfilter(struct=mystruct,callback=callback,parallel=true,maxthreadcount=40)[ 
 "key889"]) 
 try{ 
 writeoutput(structfilter(struct=mystruct,callback=callback,parallel=true,maxthreadcount=-20)[ 
 "key889"]) 
 } 
 catch(any e){ 
  writeoutput("<br>Type: " & e.type & " Message:" &  e.message ) 
 } 
 try{ 
 mystruct.filter(callback,true,100)} 
 catch(any e){ 
  writeoutput("<br>Type: " & e.type & " Message:" &  e.message ) 
 } 
</cfscript>