[Java] Draw a simple pattern

At the brain teaser level, I made a code to draw a simple pattern. Originally created as an assignment for newcomers at work, it may be a bit of a test for Java beginners.

Draw a fine checkered pattern (check)

Output image

*.*.*.*.*.
.*.*.*.*.*
*.*.*.*.*.
.*.*.*.*.*
*.*.*.*.*.
.*.*.*.*.*
*.*.*.*.*.
.*.*.*.*.*
*.*.*.*.*.
.*.*.*.*.*

code

• Since "*" and "." Are drawn alternately in the output image, the characters to be output are switched one by one using the row number and column number.

/**
 *Draw a fine checkered pattern (check).
 * @param outputSize Drawing size (number of digits).
 */
public static void printFineCheckered(int outputSize) {

	//Move in the row direction
	for (int i=0; i<outputSize; i++) {

		//Move in the column direction
		for (int j=0; j<outputSize; j++) {

			if ((i+j)%2==0) {
				System.out.print("*");
			} else {
				System.out.print(".");
			}

		}

		//Insert a line break
		System.out.print(System.lineSeparator());

	}
}

Draw a cross

Output image

*........*
.*......*.
..*....*..
...*..*...
....**....
....**....
...*..*...
..*....*..
.*......*.
*........*

code

• "Line extending from upper left to lower right" can be easily drawn, but the condition of "line extending from lower left to upper right" may not appear suddenly or it may be easy to make a mistake.

/**
 *Draw a cross.
 * @param outputSize Drawing size (number of digits).
 */
public static void printCrossMark(int outputSize) {

	//Move in the row direction
	for (int i=0; i<outputSize; i++) {

		//Move in the column direction
		for (int j=0; j<outputSize; j++) {

			if (i==j) {
				//A line extending from the upper left to the lower right
				System.out.print("*");
			} else if (i+j==outputSize-1) {
				//A line extending from the lower left to the upper right
				System.out.print("*");
			} else {
				System.out.print(".");
			}

		}

		//Insert a line break
		System.out.print(System.lineSeparator());

	}
}

Draw a checkered pattern (check)

Output image

• It is hard to see on this screen, but if you paste the following output image into a text editor, the checkered pattern will be easier to understand.

**..**..**
**..**..**
..**..**..
..**..**..
**..**..**
**..**..**
..**..**..
..**..**..
**..**..**
**..**..**

code

• The checkered pattern is a block in units of "4 rows and 4 columns", so it seems that one of the keys is whether or not you can discover and understand it.
• I don't think the code itself is that difficult, as shown below.

/**
 *Draw a checkerboard pattern.
 * @param outputSize Drawing size (number of digits).
 */
public static void printIchimatsu(int outputSize) {

	//Move in the row direction
	for (int i=0; i<outputSize; i++) {

		//Move in the column direction
		for (int j=0; j<outputSize; j++) {

			int rowIndex = i%4;
			int colIndex = j%4;

			if (rowIndex<2 && colIndex<2) {
				System.out.print("*");
			} else if (rowIndex>=2 && colIndex>=2) {
				System.out.print("*");
			} else {
				System.out.print(".");
			}

		}

		//Insert a line break
		System.out.print(System.lineSeparator());

	}

}