In a 20-character feed, count the number of a characters A.

Store the character feed into an array or list
Parse through the list with a for loop
Check the condition with if statement
Store each occurrence into a separate list if need
Then check the stored length field.
Or count +=1 to every new occurrence
Output total count as the number of occurrence

Character_feed =[a,a,...]
Count = 0
number_of_occurence = ‘A’

For (data in character_feed). // check to make sure list is not empty
If(number_of_occurence in data)
Count +=1
Else
Move to the next data in list

You can as well remove the else part.
After the operation is done
Output total count number.

This should help