BvP 2 - Chapter 3 - Selection

What is a conditional statement?

A statement that allows decisions in code based on conditions.

Syntax of an if statement

A way to execute code only when a condition is true.

Relational operators

Symbols used to compare values, like greater than or equal to.

Difference between assignment and equality testing

Assignment sets a value; equality checks if values are the same.

Example: Check if a number is odd

Test if the remainder when divided by 2 is not zero.

How to compare strings

Use equality or inequality operators to check if strings are the same or different.

What is lexicographical order?

String comparison based on alphabetical or ASCII order.

Operations for testing substrings

Check if a substring exists within a string using logical operators.

What is a nested branch?

A conditional statement placed inside another conditional statement.

Syntax of elif

Used to check additional conditions after the first condition is false.

What is a match/case statement?

A way to handle multiple cases in a cleaner format introduced in Python 3.10.

Boolean operators

Logical operators like and, or, and not used to combine conditions.

Use of and

Both conditions must be true for the result to be true.

Use of or

At least one of the conditions must be true for the result to be true.

Use of not

Inverts the truth value of a condition.

Check if two floats have the same sign

Test if both numbers are either positive or negative.

Input validation for age

Ensure the age is within a specific range before proceeding.

What to do in nested branching?

Test specific conditions first, then general conditions.

Common mistake in multiple conditions

Forgetting to use elif, leading to unnecessary checks.

Purpose of relational operators

To compare two values and return a true or false result.

Difference between greater than and greater than or equal

One includes equality, while the other excludes it.

Purpose of lexicographical order

To compare strings in a way similar to dictionary order.

How to test if a string ends with a specific substring

Use substring testing to check for a specific ending.

Difference between uppercase and lowercase in comparison

Uppercase letters are evaluated as smaller than lowercase.

Purpose of nested branches

To handle complex decision trees by embedding conditions.

Alternative to nested branches

Use elif to simplify and flatten the decision structure.

Example of a special case in conditions

Handle exceptions or outliers before general cases.

Key advantage of match/case

More readable and structured for multiple conditions.

What happens if no match in a case statement?

The default action is taken if defined.

Difference between and and or

And requires all conditions to be true, or requires at least one true.

Purpose of not

To reverse or negate the condition being checked.

Example of a boolean variable

A variable that holds either true or false.

When to use range checking

To verify if a value falls between two limits.

How to simplify logic with not

Use not to reduce the complexity of multiple checks.

What is equality testing for strings?

Checking if two strings have identical content.

Example of a multiway branching

Using multiple elif statements to test various conditions.

Key to writing efficient branching

Place the most likely conditions first to minimize checks.

Testing for case sensitivity

Ensure comparisons account for the exact casing of strings.

Common mistake in boolean logic

Confusing and with or, leading to incorrect result