[Ch6] GameHelper: trying to reduce magic maths. Adding toString; simplifying... (aee7926b) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch6/GameHelper.java

+19 −12

Changes for src/main/java/ch6/GameHelper.java: 19 added lines, 12 removed lines.
Original line number	Diff line number	Diff line
		@@ -22,7 +22,7 @@ public class GameHelper {

		public ArrayList<String> placeStartup(int startupSize) {
		ArrayList<String> alphaCells = new ArrayList<String>();
		// holds ‘f6' type coords
		// holds index to grid (0 - 48)
		int[] coords = new int[startupSize]; // current candidate coords
		int attempts = 0; // current attempts counter
		boolean success = false; // flag = found a good location ?
		@@ -55,19 +55,26 @@ public class GameHelper {
		}
		} // end while

		int i = 0; // turn location into alpha coords
		int row = 0;
		int column = 0;
		String temp = null; // temporary String for concat
		while (i < startupSize) {
		grid[coords[i]] = 1; // mark master grid pts. as ‘used'
		row = (int) (coords[i] / GRID_LENGTH); // get row value
		column = coords[i] % GRID_LENGTH; // get numeric column value
		temp = String.valueOf(ALPHABET.charAt(column)); // convert to alpha
		for (int index : coords) { // turn location into 'a0'-style coords
		grid[index] = 1; // mark master grid pts. as ‘used'
		int row = index / GRID_LENGTH; // get row value
		int column = index % GRID_LENGTH; // get numeric column value

		alphaCells.add(temp.concat(Integer.toString(row)));
		i++;
		String letter = ALPHABET.substring(column, column + 1); // convert column index to letter
		alphaCells.add(letter + row);
		}
		return alphaCells;
		}

		@Override
		public String toString() {
		StringBuilder str = new StringBuilder();
		for (int i = 0; i < grid.length; i++) {
		if (i % 7 == 0) {
		str.append("\n");
		}
		str.append(grid[i]).append(", ");
		}
		return str.toString();
		}
		}
		No newline at end of file

src/test/java/ch6/GameHelperTest.java

0 → 100644

+31 −0

Changes for src/test/java/ch6/GameHelperTest.java: 31 added lines, 0 removed lines.
Original line number	Diff line number	Diff line
		package ch6;

		import org.junit.jupiter.api.Test;

		import static org.junit.jupiter.api.Assertions.assertEquals;

		class GameHelperTest {
		@Test
		void shouldGetCharAsIntValue() {
		char a = 'a';
		assertEquals(97, a);
		}

		@Test
		void shouldConvertIntToCharA() {
		// given
		int columnIndex = 0;

		// expect
		assertEquals('a', columnIndex + 97);
		}

		@Test
		void shouldConvertIntToCharG() {
		// given
		int columnIndex = 6;

		// expect
		assertEquals('g', columnIndex + 97);
		}
		}
		No newline at end of file