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Engineering LibreTexts

6.6: Looping and Counting

  • Page ID
    3093
  • The following program counts the number of times the letter a appears in a string:

    Code \(\PageIndex{1}\) (Python):

    %%python3
    
    word = 'banana'
    count = 0
    for letter in word:
        if letter == 'a':
            count = count + 1
    print(count)
    
    

    This program demonstrates another pattern of computation called a counter. The variable count is initialized to 0 and then incremented each time an a is found. When the loop exits, count contains the result: the total number of a's.

    Exercise 3:

     

    Encapsulate this code in a function named count, and generalize it so that it accepts the string and the letter as arguments.