Jagged Arrays & Table Formatting
Handle jagged 2D arrays and print aligned tables using per-column widths; demo builds a sample matrix without Scanner.
Jagged Concept
Jagged 2D arrays: each row can have a different length. Treat rows separately, never assume a common column count.
Create Jagged
Create a jagged array by allocating rows with different lengths. The message explains why: we only need as many columns as each row requires.
public class Main {
public static void main(String[] args) {
// Create a jagged array with 3 rows of varying lengths
int[][] m = new int[3][];
// Row 0 has 2 columns
m[0] = new int[]{1, 2};
// Row 1 has 3 columns
m[1] = new int[]{3, 4, 5};
// Row 2 has 1 column
m[2] = new int[]{6};
// Print the jagged array
System.out.println("Jagged array contents:");
for (int r = 0; r < m.length; r++) {
for (int c = 0; c < m[r].length; c++) {
System.out.print(m[r][c] + " ");
}
System.out.println(); // new line after each row
}
}
}