Finding and counting duplicates in a list

procedure( MpFindDuplicated( lx )
let( (myTable)
myTable = makeTable("myTable" 0)
foreach( e lx
myTable[e] = 1 + myTable[e]
)

foreach( e myTable~>?
if( myTable[e] == 1 then
remove(e myTable)
)
)
;; return value
myTable
)
)

myList = list("a" "b" "c" "a" "d" "f" "a" "c" "b")
duplicated = MpFindDuplicated(myList)
printf("%L\n" duplicated~>??)

Output will be something like : ("a" 3 "b" 2 "c" 2)

Marcel Preda said:

foreach( e myTable~>?
if( myTable[e] == 1 then
remove(e myTable)
)

Marcel - a small change - you don't really need to do myTable->? here because if you do a foreach over a table the loop variable will be set to each key anyway. So you can just do:

foreach(e myTable
...
)

Marcel Preda said:

foreach( e myTable~>?
if( myTable[e] == 1 then
remove(e myTable)
)

Marcel - a small change - you don't really need to do myTable->? here because if you do a foreach over a table the loop variable will be set to each key anyway. So you can just do:

foreach(e myTable
...
)

Hi Andrew,

The code is not working. As its throwing error for make table command. Showing "undefined function: myTable"

LakshmanQual said:

The code is not working. As its throwing error for make table command. Showing "undefined function: myTable"

You must have made a typo somewhere - the code above that Marcel gives (or my suggested modification) can't cause that error.

My guess is that somewhere  you have (myTable) or myTable() - with parentheses around the name (not sure where you've done this). Perhaps you can paste the code which is failing and the exact error you're getting?

Regards,

Andrew.

Please double check that you use square brackets where it is needed. E.g. myTable[e] , and not myTable(e)

Hi Marcel and Andrew, Thanks for the script. Its working fine.