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Java 2D array visualizer

A 2D array in Java is an array of rows, where each row is its own array. Step through the nested loops and watch every cell fill in, row by row.

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Call stack

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What to watch

  • new int[3][4] makes three row arrays, each with four zeros.
  • The outer loop picks a row and the inner loop walks across its columns.
  • grid[row].length is the number of columns in that row.

Try changing it

  • Swap the loops so it fills column by column.
  • Make the rows different lengths and see how the arrays change.

Edit the code above and press Visualize to see your version run.

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