89_nested_loops.txt

Section 09: Nested Loops
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Nested Loops

	- Loop nested within another loop

	- Can be as many levels deep as the program needs

	- Very useful with multi-dimensional data structures

	- Outer loop vs Inner loop


Example 1

	for (outer_val {1}; outer_val <= 2; ++ outer_val)
		for (inner_val {1}; inner_val <= 3; ++inner_val)
			cout << outer_val << ", " << inner_val << endl;

	Note: inner loop loops "faster"


Example 2 - Multiplication Table

	for (int num1 {1}; num1 <= 10; ++num1) {
		for (int num2; num2 <= 10; ++num2) {
			cout << num1 << " * " << num2
			     << " = " << num1 * num2 << endl;
		}
		cout << "--------------------" << endl;
	}

	Displays 10 x 10 Multiplication Table


Example 3 - 2D Arrays - Set all Elements to 1000

	int grid[5][3] {};

	for (int row {0}; row < 5; ++row) {
		for (int col {0}; col < 3; ++col) {
			grid[row][col] = 1000;
		}
	}


Example 4 - 2D Arrays - Display Elements

	for (int row {0}; row < 5; ++row) {
		for (int col {0}; col < 3; ++col) {
			cout << grid[row][col] << " ";
		}
		cout << endl;
	}


Example 5 - 2D Vector - Display Elements

	vector<vector<int>> vector_2d {
		{1, 2, 3},
		{10, 20, 30, 40},
		{100, 200, 300, 400, 500}
	};

	for (auto vec: vector_2d) {
		for (auto val: vec) {
			cout << val << " ";
		}
		cout << endl;
	}