Conditional Statements and Program Flow

These flashcards cover key concepts related to conditional statements and program flow as discussed in the lecture.

Conditional Statement

Code that runs only when a specific condition is true, used to control the flow of a program based on decisions.For example, an if statement runs code only if a condition is met.

When would you use a conditional?

They are used when a program needs to make decisions. They allow different outcomes based on input or conditions. For example, checking if a number is positive or negative uses a conditional.

If Statement

A conditional statement that checks a condition and runs code if that condition is true.  It is the most basic form of a conditional. For example, if x > 5: runs code only when x is greater than 5.

else Statement

Runs code when the if condition is false, providing an alternative outcome. For example, if a number is not greater than 5, the else block will run instead.

elif Statement

Checks additional conditions if the first condition is false, allowing multiple conditions to be evaluated. For example, it can check if a number is positive, negative, or zero.

Comparison Operators

Operators that compare two values and return a Boolean result, used to create conditions in programs. For example, > checks if one value is greater than another.

Difference between = and ==

= is an assignment operator that sets a value, while == is a comparison operator that checks equality between two values. For example, x = 5 sets a value, while x == 5 checks if it equals 5.

What does != mean?

Operator that checks if two values are different; returns true if they are not equal. For example, x != 5 is true if x is not equal to 5.

What does >= mean?

The >= operator means “greater than or equal to.” It checks if one value is at least as large as another. For example, x >= 10 is true if x is 10 or greater.

Nested Conditional

A conditional statement placed inside another conditional statement, used for complex condition checks. For example, an if statement inside another if statement creates a nested structure.

Short-Circuit Evaluation

A logical expression evaluation that stops once the result is known, improving efficiency in condition checking. For example, in an AND condition, if the first part is false, the rest is not checked.

Boolean Expression

An expression that evaluates to true or false, used in conditionals to control program flow. For example, x > 3 is a Boolean expression.

Conditionals Control Program Flow

Conditionals determine code execution parts based on conditions, guiding the program’s decision-making. For example, different code runs depending on whether a condition is true or false.

What happens if a condition is false?

If a condition is false, the code inside the if block does not run. The program either moves on or executes an else block. For example, an else statement handles the false case.

Input Validation

Checks if user input meets conditions to prevent errors and ensure correct data. For example, checking if input is a number before processing it.

Real-World Example of Conditionals

Conditionals are used in real-world decision-making processes. They help systems respond differently based on conditions. For example, a login system checks if a password is correct.

What is a logical AND

Logical AND requires all conditions to be true. It is used to combine multiple conditions. For example, (x > 5 and x < 10) is true only if both conditions are true.

What is a logical OR?

Logical OR requires at least one condition to be true. It is used when multiple possibilities are acceptable. For example, (x < 5 or x > 10) is true if either condition is true.

What is a logical NOT

Logical NOT reverses the value of a Boolean expression. It turns true into false and vice versa. For example, not(x > 5) is true when x is not greater than 5.

Importance of Conditionals

They allow programs to make decisions, enabling dynamic and flexible behavior based on user input. For example, programs can respond differently based on user input.