ListEach
Used to iterate over a delimited list and run the function closure for each item in the list.
This BIF is similar to the ArrayEach BIF, but operates on a delimited list instead of an array.
Parallel Execution
If the parallel argument is set to true, and no max_threads are sent, the filter will be executed in parallel using a ForkJoinPool with parallel streams.
If max_threads is specified, it will create a new ForkJoinPool with the specified number of threads to run the filter in parallel, and destroy it after the operation is complete.
Please note that this may not be the most efficient way to iterate, as it will create a new ForkJoinPool for each invocation of the BIF. You may want to consider using a shared ForkJoinPool for better performance.
Method Signature
ListEach(list=[string], callback=[function:Consumer], delimiter=[string], includeEmptyFields=[boolean], multiCharacterDelimiter=[boolean], parallel=[boolean], maxThreads=[integer], ordered=[boolean])Arguments
list
string
true
The delimited list to perform operations on
callback
function:Consumer
true
The function to invoke for each item. The function will be passed 3 arguments: the value, the index, the array. You can alternatively pass a Java Consumer which will only receive the 1st arg.
delimiter
string
false
string the list delimiter
,
includeEmptyFields
boolean
false
boolean whether to include empty fields in the returned result
false
multiCharacterDelimiter
boolean
false
boolean whether the delimiter is multi-character
true
parallel
boolean
false
Whether to run the filter in parallel. Defaults to false. If true, the filter will be run in parallel using a ForkJoinPool.
false
maxThreads
integer
false
The maximum number of threads to use when running the filter in parallel. If not passed it will use the default number of threads for the ForkJoinPool. If parallel is false, this argument is ignored.
ordered
boolean
false
(BoxLang only) whether parallel operations should execute and maintain order
false
Examples
List Loop using listEach
Using a semicolon delimiter.
list = "a;b;c";
listEach( list, ( Any element, Any index, Any list ) => {
writeOutput( "#index#:#element#;" );
}, ";" );
Result: 1:a;2:b;3:c;
Member Function Example
List Loop list.listEach()
list = "a;b;c";
list.listEach( ( Any element, Any index, Any list ) => {
writeOutput( "#index#:#element#;" );
}, ";" );
Result: 1:a;2:b;3:c;
Example using a Closure
Example 1
empArray = [
"john",
"pete",
"bob"
];
listS = "'john', 'pete', 'bob'";
arrayEach( empArray, xclosure );
listEach( listS, xclosure );
function xclosure( Any empname, Any index ) {
writeOutput( empName & " at index: " & index );
}
Result: john at index: 1pete at index: 2bob at index: 3'john' at index: 1 'pete' at index: 2 'bob' at index: 3
Another Closure Example
Example 2
cityList = "Pittsburgh, Raleigh, Miami, Las Vegas";
function printCity( String city ) {
writeOutput( "Current city: " & city );
}
listEach( cityList, printCity );
Result: Current city: PittsburghCurrent city: RaleighCurrent city: MiamiCurrent city: Las Vegas
Additional Examples
list = "Plant,green,save,earth";
listEach( list, ( Any element, Any index, Any list ) => {
writeOutput( "#index#:#element#;<br>" );
} );
// Member function with custom delimiter
writeOutput( "<br>Member Function<br>" );
strLst = "one+two+three";
strLst.listEach( ( Any element, Any index, Any list ) => {
writeOutput( "#index#:#element#;<br>" );
}, "+" );
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