AP CSA Unit 4 Day 23: 2D Array Row Sums
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Unit 4, Data Collections • Cycle 2
Day 23 Advanced Practice • Harder Difficulty
Focus: 2D Array Row Sums
Hard
2D Array Row Sums
Advanced Practice Question
Format: 2D Array Row Sums
What is the output?
What is the output?
int[][] matrix = {
{1, 2},
{3, 4},
{5, 6}
};
int total = 0;
for (int r = 0; r < matrix.length; r++) {
for (int c = 0; c < matrix[r].length; c++) {
total += matrix[r][c];
}
}
System.out.println(total);
Difficulty: Hard |
Topic: 2D Array Row Sums |
Cycle: 2 (Advanced)
Why This Answer?
Sums all elements: 1+2+3+4+5+6 = 21.
Common Mistake
Watch Out!
Thinking it sums only one row or column.
AP Exam Strategy
Nested loops sum ALL elements: outer=rows, inner=columns.
Master This Topic
This Cycle 2 HARD question tests 2d array row sums. Review Unit 4 concepts to build mastery of data collections.
- Understanding 2d array row sums
- Tracing code execution accurately
- Avoiding common pitfalls
Ready for More Challenges?
Cycle 2 questions prepare you for the hardest AP CSA exam questions.
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