Boolean Expressions: every key term you need

Boolean Type

true or false; result of logical expressions. Used in conditionals (if), loops. Variables: boolean isPassed = true;

Comparison Operators

== (equal), != (not equal), < (less), > (greater), <= (less/equal), >= (greater/equal). Return boolean.

Logical AND (&&)

Both conditions true → true. Otherwise false. Short-circuit: if left false, right not evaluated.

Logical OR (||)

At least one true → true. Both false → false. Short-circuit: if left true, right not evaluated.

Logical NOT (!)

Inverts boolean: !true = false, !false = true. Applied to single boolean or expression.

De Morgan's Laws

!(A && B) = !A || !B. !(A || B) = !A && !B. Useful for simplifying complex conditions.

If Statement

if (condition) { statements if true } else { statements if false }. Condition must be boolean.

Nested If Statements

If inside if. Use braces carefully for clarity. Indentation shows nesting; braces required for multiple statements.

If-Else-If Chains

if (cond1) { } else if (cond2) { } else { }. Evaluates conditions in order; executes first true block only.

Ternary Operator

(condition) ? value_if_true : value_if_false. Compact if-else. Example: max = (a > b) ? a : b;

Switch Statement

switch (value) { case 1: ...; break; default: ... }. Cleaner than many if-else for discrete values.

Switch Break Statement

break exits switch; omitting it causes fall-through to next case. Use intentionally or always break.

Unit 3 Summary

Boolean logic: && (and), || (or), ! (not). Comparisons return booleans. If-else structures decision flow. Ternary operator = compact if-else.

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