Question

Assume the following declaration appears in a program: Declare String str = "Tiger" Write a statement that changes the str variable's first character to \(^{*} \mathrm{L}^{\prime \prime}\)

Short answer

Answer: The steps involved in changing the first character of the given string "Tiger" to "L" are: 1. Identify the given string, which is "Tiger". 2. Extract everything but the first character from the original string, resulting in "iger". 3. Combine the desired new character "L" with the remaining string "iger" to get the modified string "Liger". 4. Assign the new string to the original variable 'str'.

Step-by-step solution

Identify the given string

The given string is "Tiger". Here is its declaration: Declare string str = "Tiger"

Extract the first character from the original string

To change the first character, first extract everything but the first character, which is "iger" in this case. This can be done using the substring function that most programming languages provide: Declare string remainingString = str.Substring(1)

Combine the new character with the remaining string

Now, combine the desired new character "L" with the remaining string "iger" to get the modified string "Liger": Declare string modifiedString = "L" + remainingString

Assign new string to the original variable

Finally, assign the new string to the original variable 'str': str = modifiedString

Key concepts

Programming Logic

In simple terms, programming logic refers to the reasoning and algorithms behind the code that you write. It is the backbone of every program, ensuring things happen in an orderly and efficient manner. Programming logic involves:

• Understanding the problem you're solving.
• Breaking it down into smaller, more manageable tasks.
• Designing algorithms or step-by-step instructions to solve these tasks.

For example, in the problem of changing the first character of a string, programming logic helps you decide:

• Which operations you need to perform, such as extracting part of the string and combining it with a new character.
• In which order these operations should happen, for example, extracting the substring before updating the original string.

Mastering programming logic allows you to think critically and solve complex problems with a structured approach.

Substring Function

The substring function is a powerful tool in the toolbox of string manipulation functions. It allows you to extract specific parts of a string, which are called substrings, based on their position. Here's how it typically works:

• You specify a starting point (and sometimes an endpoint).
• The function returns the section of the string from that start point, optionally up to the endpoint.

In many programming languages, strings are zero-indexed, meaning the first character has an index of 0. Therefore, to remove the first character and keep the rest, you'd use: ```python str.Substring(1) ``` This call starts extraction from the second character (index 1) and continues to the end. Understanding how to use substring functions is crucial for efficient string manipulation, as it allows you to dissect and manipulate text data for your specific needs.

Variable Assignment

Variable assignment in programming is the process of storing data in a variable, which is a named space in memory. The principle of variable assignment is straightforward:

• Choose a variable name that meaningfully represents the data it holds.
• Assign it a specific value using an assignment operator, like `=` in most languages.

For instance, when you assign a new string to an already declared variable, like in our task: ```python str = modifiedString ``` It updates the content of `str` with the new value held by `modifiedString`. This operation makes variables dynamic in that they can hold different data at different times during program execution.
In our example, `str` initially held the value "Tiger", and through assignment, it is updated to "Liger". This demonstrates the flexibility and power of variables in programming, allowing for data changes and manipulation according to the logic of your program.