Parameter
Cập nhật gần đây nhất vào
26 thg 12, 2022
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Cũng áp dụng cho ColdFusion
Description
Filters the key-value pairs in a struct.
Returns
Filtered struct.
Category
Syntax
structFilter(struct,callback [, parallel] [, maxThreads])
History
ColdFusion (2021 release): Introduced the following parameters:
- parallel
- maxThreadCount
ColdFusion (2018 release): Introduced named parameters.
ColdFusion 10: Added this function.
Parameters
|
|
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. |
|
maxThreads |
(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))
return false
else if(isSimplevalue(val) && key eq 'key889')
{
return true
}
else return false
}
t_start=GetTickCount()
writedump(mystruct.filter(callback))
t_end=GetTickCount()
writedump("Time taken with no parallel:" & t_end-t_start)
t_start=GetTickCount()
writedump(mystruct.filter(callback,true,5));
t_end=GetTickCount()
writedump("Time taken with 5 threads:" & t_end-t_start)
t_start=GetTickCount()
writedump(mystruct.filter(callback,true,10))
t_end=GetTickCount()
writedump("Time taken with 10 threads:" & t_end-t_start)
t_start=GetTickCount()
writedump(structfilter(struct=mystruct,callback=callback,parallel=true,maxthreadcount=20))
t_end=GetTickCount()
writedump("Time taken with 20 threads:" & t_end-t_start)
t_start=GetTickCount()
writedump(structfilter(struct=mystruct,callback=callback,parallel=true,maxthreadcount=40))
t_end=GetTickCount()
writedump("Time taken with 40 threads:" & t_end-t_start)
</cfscript>
