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What possible outputs(s) will be obtained when the following code is executed?
Options:
a.
RED*
WHITE*
BLACK*
RED*
b.
YELLOW*
WHITE*
BLACK*
RED*
c.
WHITE* WHITE*
YELLOW* YELLOW*
BLACK* BLACK*
RED* RED*
d.
YELLOW*
WHITE*WHITE*
BLACK* BLACK* BLACK*
RED* RED* RED* RED* RED*
Answer
Answer by student:
b. YELLOW*
WHITE*
BLACK*
RED*
Detailed answer by teachoo:
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To answer this question, we need to know the syntax and usage of random, lists, and nested loops in Python.
- The random module is a built-in module that provides various functions to generate random numbers and choices. We can import the random module using the import statement. For example, import random will import the random module.
- The randint(a,b) function is a function in the random module that returns a random integer between a and b, inclusive. For example, random.randint(0,3) will return a random integer from 0, 1, 2, or 3.
- A list is a data structure that stores a sequence of mutable values, which means they can be changed after creation. A list is created by enclosing the values in square brackets [] and separating them by commas. For example, COLOR = [“YELLOW”,“WHITE”,“BLACK”,“RED”] is a list that stores four string values.
- A loop is a control structure that allows us to repeat a block of code for a certain number of times or until a condition is met. There are two types of loops in Python: for loop and while loop. A for loop is used to iterate over a sequence of values, such as a list or a range. A while loop is used to repeat a block of code as long as a condition is true.
- A nested loop is a loop inside another loop. The inner loop executes for each iteration of the outer loop. The indentation level indicates which loop belongs to which block of code.
Let’s go through each of the options and see why they are correct or incorrect:
- a. RED*
WHITE*
BLACK*
RED*
This is incorrect because it repeats "RED" twice, which is not possible based on the code.
- b. YELLOW*
WHITE*
BLACK*
RED*
This is correct because it matches the output of the code when myNumber = 1. The code will print each color followed by an asterisk (*) for myNumber - 1 times in each line. The value of myNumber is randomly chosen from 0 to 3, so it can be 1 for some executions. The order of the colors is the same as the list COLOR.
- c. WHITE* WHITE*
YELLOW* YELLOW*
BLACK* BLACK*
RED* RED*
This is incorrect because it repeats each color twice on each line, which is not the expected behavior of the code.
- d. YELLOW*
WHITE*WHITE*
BLACK* BLACK* BLACK*
RED* RED* RED* RED* RED*
This is incorrect because each color is repeated, but the number of repetitions does not match the value of myNumber - 1.
So, the correct answer is
b. YELLOW*
WHITE*
BLACK*
RED*
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