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Article ID: KB0076744
                        
                    
                    
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Updated On: 
                    
                 
                
                        
                            
Description
                        
                        
                            I have a list..
[1,2,3,4,5,4,4,5]
..and I would like to count how many elements match the value 4.
                        
 
                     
                    
                    
                    
                    
                        
                            
                                
Resolution
                            
                            
                                To get this value, you can use a combination of length() and filterlist() functions in a Map operator, as described in the Help under 
Home > StreamBase References > StreamBase Expression Language Functions.  For example..
length(filterlist(input1.ListOfInts, function myrange(x int) { x == 4} ))
..where 'ListOfInt' is the input list field going into the Map operator.
                            
 
                        
                    
                        
                            
                                
Issue/Introduction
                            
                            
                                This article describes how to get a count of list elements that match a certain value.