Question

The following procedure is intended to return the number of times the value 'val' appears in my list. What is the missing code?

a. count(val)
b. find(val)
c. occurrences(val)
d. list.count(val)

Answer 1

The missing code in the student's procedure to count the occurrences of 'val' in a list is 'list.count(val)', which is option d. The count() method is a built-in function in Python that returns the count of how many times a given object occurs in a list.

Step-by-step explanation:

The procedure mentioned is intended to return the number of times a specific value appears in a list. In Python, lists are a type of data structure that can store multiple items. To count the occurrences of a particular element in a list, Python provides a built-in method called count(). The correct option to complete the procedure is d. list.count(val). When count() is called on a list, followed by a value as an argument, it returns an integer representing the number of times that value appears in the list.

Here's an example of how count() is used:

my_list = [1, 2, 3, 2, 1, 3, 4, 2, 1]
val = 2
print(my_list.count(val))

This would output 3, as the value 2 appears three times in my_list. To answer the question, one would replace the placeholder with d. list.count(val) in the provided procedure.