The correct answer is A. key-value pairs.
A dictionary is a data structure that maps keys to values. The keys are unique identifiers for the values, and the values can be any type of data. Dictionaries are often used to store data in a way that is easy to access and search.
Here is an example of a dictionary:
{
"name": "John Doe",
"age": 30,
"address": "123 Main Street, Anytown, CA 91234"
}
In this example, the keys are “name”, “age”, and “address”. The values are “John Doe”, 30, and “123 Main Street, Anytown, CA 91234”.
Dictionaries can be created using the {} syntax. For example, the following code creates a dictionary with two keys and two values:
my_dictionary = {"name": "John Doe", "age": 30}
Dictionaries can be accessed using the [] syntax. For example, the following code prints the value of the “name” key:
print(my_dictionary["name"])
The output of this code is “John Doe”.
Dictionaries can be updated using the []= syntax. For example, the following code updates the value of the “age” key to 31:
my_dictionary["age"] = 31
Dictionaries can be deleted using the del keyword. For example, the following code deletes the “name” key:
del my_dictionary["name"]
The output of this code is KeyError: "name".
Dictionaries are a powerful data structure that can be used to store and organize data in a variety of ways. They are often used in programming languages such as Python, JavaScript, and Java.