P1(algorithms and coding) mock content

Question 1

What is string concatenation?

Answer 1

String concatenation is the operation of joining two or more strings end-to-end to form a single string.

Example: “Hello, “ + “World!” results in “Hello, World!”

Question 2

How do you find the length of a string in Python?

Answer 2

You use the len() function to find the number of characters in a string.

Example: len(“Hello”) results in 5

Question 3

What is a substring?

Answer 3

A substring is a portion of a string, extracted from the original string based on specified start and end indices.

Example: “abcdef”[1:4] results in “bcd”

Question 4

How do you access a specific character in a string in Python?

Answer 4

You can access a specific character in a string using its index.

Example: “Hello”[1] results in “e”

Question 5

What function would you use to replace part of a string in Python?

Answer 5

The function used is replace(), which replaces specified parts of the string with a new substring.

Example: “Hello World”.replace(“World”, “Python”) results in “Hello Python”

Question 6

What does the strip() function do to a string in Python?

Answer 6

The strip() function removes whitespace from both the beginning and end of a string.

Example: “ Hello “.strip() results in “Hello”

Question 7

How do you split a string into an array of substrings in Python?

Answer 7

You use the split() method, which splits a string based on a delimiter.

Example: “a,b,c”.split(“,”) results in [‘a’, ‘b’, ‘c’]

Question 8

How can you convert all characters in a string to uppercase in Python?

Answer 8

You use the upper() method.

Example: “hello”.upper() results in “HELLO”

Question 9

What is the purpose of the find() method in Python?

Answer 9

The find() method returns the index of the first occurrence of a specified substring within a string.

Example: “Hello World”.find(“World”) results in 6

Question 10

What is pseudocode?

Answer 10

Pseudocode is a simplified, informal way of writing programming logic that uses plain English to describe the steps in an algorithm.

Question 11

Why is pseudocode useful?

Answer 11

Pseudocode helps programmers plan and visualize the logic of their algorithms before writing actual code. It focuses on logic rather than syntax.

Question 12

Read the following pseudocode and determine the output: SET total TO 0 FOR each number FROM 1 TO 5 SET total TO total + number ENDFOR OUTPUT total

Answer 12

The output is 15. This loop adds the numbers 1 through 5, resulting in 1 + 2 + 3 + 4 + 5 = 15.

Question 13

What does the following pseudocode do? SET count TO 0 FOR each item IN list IF item > 10 THEN INCREMENT count BY 1 ENDIF ENDFOR OUTPUT count

Answer 13

The pseudocode counts the number of items in the list that are greater than 10 and outputs the count.

Question 14

What is decomposition?

Answer 14

Decomposition is the process of breaking down a problem into a number of sub-problems, so that each sub-problem accomplishes an identifiable task, which might itself be further subdivided.

Question 15

What is abstraction?

Answer 15

The process of removing unnecessary detail for my problem.

Question 16

How do you define a function in Python?

Answer 16

You use the def keyword followed by the function name and parentheses.

Example:
def greet(name):
print(f”Hello, {name}”)

Question 17

What is the purpose of the return statement in Python?

Answer 17

The return statement exits a function and optionally passes back an expression to the caller.

Example:
def add(a, b):
return a + b

Question 18

How do you call a function in Python?

Answer 18

You call a function by using its name followed by parentheses.

Example:
greet(“Alice”)

Question 19

Read the code and determine the output: def add(a, b): return a + b print(add(3, 4))

Answer 19

The output is 7.

Question 20

What will the output be for the following code? for i in range(3): print(i)

Answer 20

The output will be:
0
1
2

Question 21

What is the purpose of a trace table?

Answer 21

A trace table helps track the values of variables at each step of an algorithm to ensure the logic is correct.

Question 22

Complete the trace table for the following code: total = 0 for i in range(1, 4): total += i print(total)

Answer 22

i total
1 1
2 3
3 6

Question 23

What is the trace table for the following pseudocode? SET sum TO 0 FOR i FROM 1 TO 3 SET sum TO sum + i ENDFOR

Answer 23

i sum
1 1
2 3
3 6

Question 24

Write pseudocode to find the largest number in a list.

Answer 24

SET max TO list[0] FOR each number IN list IF number > max THEN SET max TO number ENDIF ENDFOR OUTPUT max

Question 25

Write Python code to find the largest number in a list.

Answer 25

def find_max(numbers):
max_num = numbers[0]
for num in numbers:
if num > max_num:
max_num = num
return max_num
print(find_max([3, 7, 2, 9, 5]))

Question 26

What are the key differences between linear search and binary search?

Answer 26

Linear search checks each element in the list sequentially until the target element is found or the list ends, making it simple but potentially slow. Binary search, on the other hand, requires a sorted list and divides the search interval in half repeatedly, which makes it much faster but more complex.

Question 27

Identify and correct the syntax error: print(“Hello, World!)

Answer 27

Error: Missing closing quotation mark. Corrected code:
print(“Hello, World!”)

Question 28

Identify and correct the syntax error: for i in range(3) print(i)

Answer 28

Error: Missing colon after the for loop. Corrected code:
for i in range(3):
print(i)

Question 29

What is a common cause of syntax errors?

Answer 29

Syntax errors are often caused by mistakes in the code’s structure, such as missing punctuation, incorrect indentation, or misusing keywords.

Question 30

What is a syntax error?

Answer 30

A syntax error occurs when the code violates the rules of the programming language, making it impossible to parse.

Question 31

What is a logic error?

Answer 31

A logic error occurs when the code runs without crashing but produces incorrect results due to faulty logic.

Question 32

What is unit testing?

Answer 32

Unit testing involves testing individual components or functions of a program to ensure they work correctly.

Question 33

What is integration testing?

Answer 33

Integration testing checks how different parts of a program work together.

Question 34

What is system testing?

Answer 34

System testing evaluates the entire system’s functionality to ensure it meets requirements.

Question 35

What is acceptance testing?

Answer 35

Acceptance testing determines if the system meets the user’s needs and is ready for deployment.

Question 36

What does the mod operator do in Python?

Answer 36

The mod operator (%) returns the remainder of a division.