Which of the following is used for testing for membership in the list of column names?

in
out
elseif
none of the mentioned

The correct answer is: A. in

The in operator is used to test for membership in a list. It takes two arguments: the first is the value to test, and the second is the list of values to test against. If the value is in the list, the operator returns true; otherwise, it returns false.

For example, the following code tests whether the value “apple” is in the list of fruits:

if "apple" in ["apple", "banana", "cherry"]
print("Yes, apple is in the list.")
else
print("No, apple is not in the list.")

The output of this code would be:

Yes, apple is in the list.

The out operator is used to test for non-membership in a list. It takes two arguments: the first is the value to test, and the second is the list of values to test against. If the value is not in the list, the operator returns true; otherwise, it returns false.

The elseif keyword is used to create a conditional statement with multiple branches. It is similar to the if keyword, but it allows you to specify multiple conditions that must be met in order for the statement to execute.

The none of the mentioned option is incorrect because it does not include the correct answer.