Day 83: Python Program to Swap the First and the Last Character of a String

 

def swap_first_last_char(string):

    if len(string) <= 1:

        return string

        swapped_string = string[-1] + string[1:-1] + string[0]

    return swapped_string

user_input = input("Enter a string: ")

result = swap_first_last_char(user_input)

print(f"String after swapping the first and last characters: {result}")

#source code --> clcoding.com 

Code Explanation:

1. The swap_first_last_char Function

def swap_first_last_char(string):

This line defines a function named swap_first_last_char, which takes a single argument, string. This function is intended to swap the first and last characters of the string.

    if len(string) <= 1:

        return string

Condition Check: This checks if the length of the string is 1 or less.

If the string has 1 character (e.g., "a") or no characters at all (empty string ""), swapping the first and last characters wouldn't change anything.

So, in this case, it returns the original string as it is.

    swapped_string = string[-1] + string[1:-1] + string[0]

Swapping Logic:

string[-1]: This accesses the last character of the string.

string[1:-1]: This accesses the middle part of the string (from the second character to the second-last character).

string[0]: This accesses the first character of the string.

The expression:

string[-1] + string[1:-1] + string[0]

Concatenates (combines) the last character, the middle part, and the first character in that order, effectively swapping the first and last characters.

    return swapped_string

After swapping the characters, this line returns the new string that has the first and last characters swapped.

2. Taking User Input

user_input = input("Enter a string: ")

This line prompts the user to input a string.

The user's input is stored in the variable user_input.

3. Calling the Function and Displaying the Result

result = swap_first_last_char(user_input)

This line calls the function swap_first_last_char with the user_input as the argument. It stores the result (the swapped string) in the variable result.

print(f"String after swapping the first and last characters: {result}")

This line prints the result (the string with the first and last characters swapped) to the console using f-string formatting.