Question 4 - Teachoo Sample Paper - Computer Science Class 12 - Solutions to CBSE Sample Paper - Computer Science Class 12

What will be the output of the following code:

s = "Hello World" 

s = s[::-1] 

s = s.title() 

s = s.replace("l", "*") 

print(s)

1. D*roW O**eh 

2. DlroW OlleH 

3. droW o**eh 

4. Dlrow Olleh 

Answer:

Answer by student

a. D*roW O**eh

Detailed answer by teachoo

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The code is written in Python and uses some string methods and slicing techniques. Let’s look at each of the options and see why they are correct or incorrect.

• a. D*roW O**eh : This is the correct option, as it matches the final value of s after applying all the string operations.
• b. DlroW OlleH : This is incorrect , as it does not replace the letter “l” with “*”.
• c. droW o**eh : This is incorrect , as it does not capitalize the first letter of each word.
• d. Dlrow Olleh : This is incorrect , as it does not reverse the string or replace the letter “l” with “*”.

To get the correct answer, we need to follow these steps:

• Reverse the string s by using a negative step of -1. The syntax for slicing is

s[start:stop:step]

• • where start is the starting index
  • stop is the ending index (not included)
  • step is the increment or decrement between each index.

• By leaving out the start and stop, we are slicing the whole string, but by using -1 as the step, we are going backwards . So, s becomes “dlroW olleH” .
• Capitalize the first letter of each word in the string s and make the rest lowercase. The title() method does this automatically. So, s becomes “Dlrow Olleh”.
• Replace all occurrences of the letter “l” in the string s with the symbol “ ". The replace(old, new) method takes two arguments: the old substring to be replaced and the new substring to replace it with. So, s becomes "D roW O**eh” .
• Print the final value of s to the output.

So, the correct answer is a. D*roW O**eh

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