# How do you create a two dimensional array in Ruby?

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## How do you declare an array with two dimensions?

To create an array use the new keyword, followed by a space, then the type, and then the number of rows in square brackets followed by the number of columns in square brackets, like this new int[numRows][numCols] . The number of elements in a 2D array is the number of rows times the number of columns.

## What is a 2D array Ruby?

Often data is two-dimensional. With the Array in Ruby, we can nest Arrays, creating 2D arrays. … With nested iterators, we loop over elements. And with built-in methods like flatten() we can transform nested arrays into 1-dimensional ones.

## How do you create a two dimensional array and what’s the syntax?

A 2D array has a type such as int[][] or String[][], with two pairs of square brackets. The elements of a 2D array are arranged in rows and columns, and the new operator for 2D arrays specifies both the number of rows and the number of columns. For example, int[][] A; A = new int[3][4];

## How do you create a matrix in Ruby?

To create a matrix:

1. Matrix.
2. [](*rows)
3. rows (rows, copy = true)
4. columns(columns)
5. build ( row_count , column_count , &block)
6. diagonal(*values)
7. scalar (n, value)
8. identity(n)

## How do you flatten an array in Ruby?

The flatten() is an inbuilt method in Ruby returns a new set that is a copy of the set, flattening each containing set recursively.

1. Syntax: s1.flatten()
2. Parameters: The function does not takes any parameter.
3. Return Value: It returns a boolean value. It returns true if the set is empty or it returns false.

## How do you fill a 2D array?

“fill a 2d array java” Code Answer’s

1. int rows = 5, column = 7;
2. int[][] arr = new int[rows][column];
3. //2D arrays are row major, so always row first.
4. for (int row = 0; row
5. {
6. for (int col = 0; col

## Which of the following is a two dimensional array?

Answer: Correct option is (B) int anarray[20][20];

## How do you create a hash in Ruby?

In Ruby you can create a Hash by assigning a key to a value with => , separate these key/value pairs with commas, and enclose the whole thing with curly braces.

## How do you create a range in Ruby?

Ranges as Sequences

Sequences have a start point, an end point, and a way to produce successive values in the sequence. Ruby creates these sequences using the ”..” and ”…” range operators. The two-dot form creates an inclusive range, while the three-dot form creates a range that excludes the specified high value.

## What is a Hash Ruby?

In Ruby, Hash is a collection of unique keys and their values. Hash is like an Array, except the indexing is done with the help of arbitrary keys of any object type. … When a user tries to access the keys which do not exist in the hash, then the nil value is returned.

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## What is the two dimensional array How do you access its elements?

A 2-dimensional array can be thought of as a table, which has x number of rows and y number of columns. An element in 2-dimensional array is accessed by using the subscripts. That is, row index and column index of the array.

## What is a double array?

A double array is basically a single-dimensional array in which each index is actually the first index of another single-dimensional array. One way to visualize a double array is as a grid, or a piece of graph paper.