AP Computer Science A: Logic & Control Structures

Algorithm

A finite sequence of well-defined instructions to solve a specific problem.

Sequencing

Executing instructions one after another in order.

Selection (Conditionals)

Deciding which part of an algorithm to run based on a boolean condition.

Iteration (Repetition)

Repeating a section of code multiple times, such as in loops.

Boolean Expression

A code snippet that evaluates to either true or false.

Relational Operators

Operators in Java used to compare primitive values, resulting in a boolean.

==

Equal to operator that checks if two values are the same.

!=

Not equal to operator that checks if two values are different.

<

Less than operator used to compare two values.

>

Greater than operator used to compare two values.

<=

Less than or equal to operator used to compare two values.

>=

Greater than or equal to operator used to compare two values.

If Statement

A control flow statement that executes a block of code when a condition is true.

Control Flow

The order in which individual statements or instructions are executed.

Single-Way Selection

A conditional structure where code runs only if the condition is true.

If-Else Statement

A conditional structure that executes one block if true, another if false.

Multi-Way Selection (Else-If)

Chained conditions that allow for multiple possible execution paths.

Logical Operators

Operators that combine boolean expressions to evaluate multiple conditions.

! (NOT)

Logical operator that inverts the boolean value.

&& (AND)

Logical operator that is true only if both operands are true.

|| (OR)

Logical operator that is true if at least one operand is true.

Short-Circuit Evaluation

Java's optimization where it skips evaluating certain operands based on prior results.

De Morgan's Laws

Rules for simplifying boolean expressions by distributing the NOT operator.

Comparing Objects

The method of checking equality for objects in Java using == or .equals().

Correct String Comparison

Use .equals() to compare String contents, not ==.

Common Mistakes in Conditionals

Includes errors like confusing = with ==, and improper use of semicolons.

Boundary Errors

Mistakes made by confusing comparison operators, leading to off-by-one errors.

Negation of Ranges

Incorrectly negating ranges in boolean expressions can lead to logical errors.