Question

If the following pseudocode were an actual program, what would it display? If "z" < "a" Then Display "z is less than a." Else Display "z is not less than a." End If

Short answer

Answer: The displayed message would be "z is not less than a."

Step-by-step solution

Understand character comparisons

To compare characters, programming languages typically compare their Unicode values. Unicode values are unique integer values assigned to each character. The characters "a" to "z" have Unicode values in the range of 97 to 122, and they are ordered alphabetically, i.e., "a" < "b" < "c" ... < "z". In this case, we are comparing "z" with "a".

Determine the outcome of the comparison

Using the alphabetical Unicode ordering, we can determine the outcome of the comparison between "z" and "a". Since "z" comes after "a" in the alphabet and has a higher Unicode value (122) than "a" (97), we can conclude that: "z" > "a" As the condition given in the pseudocode ("z" < "a") doesn't hold true, the program will execute the Else block.

Find the output of the pseudocode

As per our analysis, the Else block will be executed since the provided condition is false. So the displayed message would be: "z is not less than a."

Key concepts

Character Comparison

Character comparison is an essential concept in programming, often used to determine the "order" of characters based on their assigned values. In most programming languages, characters are compared using their Unicode values. This means that when we want to see if one character is less than, greater than, or equal to another, the comparison is made based on numerical values associated with each character rather than their alphabetical position alone.

For example, consider the comparison between the characters "z" and "a". If you were arranging these alphabetically, you might naturally conclude that "a" comes before "z". But the comparison is made numerically using their Unicode values. The language uses these numeric values for accuracy and consistency, ensuring the same result regardless of character set or context.

Conditional Statements

Conditional statements are a fundamental part of programming logic. They allow a program to decide which actions to perform based on whether a condition is true or false. These statements often follow an "if-then-else" structure, as seen in the pseudocode provided.

• "If" checks for a specific condition.
• "Then" specifies what will happen if the "if" condition is true.
• "Else" defines what happens when the "if" condition is false.

In the pseudocode example, the condition "If 'z' < 'a'" is evaluated. Because this condition evaluates to false (as 'z' has a higher Unicode value than 'a'), the program will skip the "Then" block and execute the "Else" block instead. Thus, conditional statements help in directing the program flow based on conditions derived from logical operations.

Unicode Values

Unicode is a computing industry standard that assigns unique numeric values to characters, symbols, and emojis, allowing consistent encoding and representation of text across various platforms and languages. Each character, referred to in Unicode terms as a "code point," is represented by a specific integer.

For instance, in the English alphabet:

• "a" has a Unicode value of 97
• "b" has a Unicode value of 98
• ... continuing to ...
• "z" which has a Unicode value of 122

This numeric representation is crucial for logical operations, allowing characters to be compared based on their position within a defined set. It standardizes the way different systems interpret text, preventing errors during data communication. In the pseudocode example, we utilized these Unicode values to determine the result of the character comparison.