AP Computer Science Unit 1 Review

Advanced Placement Computer Science A Unit 1 Review

Variables and Data Types

public class VariableExample {
    public static void main(String[] args) {
        // Defining and assigning a variable of type int
        int age = 25;
        
        // Defining and assigning a variable of type double
        double temperature = 26.5;
        
        // Defining and assigning a variable of type char
        char grade = 'A';
        
        // Defining and assigning a variable of type boolean
        boolean isRaining = true;
    }
}

Expressions and Assignment Statements

public class ExpressionExample {
    public static void main(String[] args) {
        int x = 10;
        int y = 5;
        
        // Arithmetic expressions
        int sum = x + y;
        int difference = x - y;
        int product = x * y;
        int quotient = x / y;
        
        // Comparison expressions
        boolean isEqual = (x == y);
        boolean isGreater = (x > y);
        
        // Logical expressions
        boolean andResult = (x > 0) && (y > 0);
        boolean orResult = (x > 0) || (y > 0);
    }
}

Compound Assignment Operators

public class CompoundAssignmentExample {
    public static void main(String[] args) {
        int x = 10;
        
        // Compound assignment operators
        x += 5; // x = x + 5;
        x -= 3; // x = x - 3;
        x *= 2; // x = x * 2;
        x /= 4; // x = x / 4;
    }
}

Casting and Ranges of Variables

public class CastingExample {
    public static void main(String[] args) {
        // Widening conversion
        int intValue = 10;
        double doubleValue = intValue; // Automatic conversion
        
        // Narrowing conversion (Caution: Data loss may occur!)
        double doubleNum = 15.75;
        int intNum = (int) doubleNum; // Manual conversion
    }
}