What code is needed to assign the number of columns of the 2nd row of a 2D array to variable colSize?
# To create 2 or more dimensional Arrays in python
# A two-dimensional array(list) is like a table with rows and columns.
# Assume there are 1, 2, 3 to n rows and 1, 2, 3 to n colums of data
# Let data at row 1,column 1; row 2, column 2, correspond to d11, d22
# col1 col2 ... coln
# row1 d11 d12 ... d1n
# row2 d21 d22 ... d2n
# . . . ... .
# . . . ... .
# . . . ... .
# rown dn1 dn2 ... dnn
# Syntax of 2d array in python:
# [[d11,d12,d13,..,d1n],[d21,d22,d23,.......,d2n]]
# Example: Following is the example for creating
# 2D array with 4 rows and 5 columns
array=[[23,45,43,23,45],[45,67,54,32,45],[89,90,87,65,44],[23,45,67,32,10]]
#display
print(array)
# Accessing the values using index position
# Syntax:
# 1) Get row value using [] operator
# i.e array[row index]
# 2) Get column value using [][]
# i.e array[row index][column index]
# where,
# row index is the row position starts from 0
# column index is the column position starts from 0 in a row.
# For instance:
# get the first row
print(array[0])
# get the third row
print(array[2])
#get the element at the first row and the third column
print(array[0][2])
# get the element (value) at the third row and forth column
print(array[2][3])
# Output:
# [[23, 45, 43, 23, 45], [45, 67, 54, 32, 45], [89, 90, 87, 65, 44], [23, 45, 67, 32, 10]]
# [23, 45, 43, 23, 45]
# [89, 90, 87, 65, 44]
# 43
# 65
# Inserting values into two-dimensional array using the insert() function
# Syntax:
# array.insert(index,[values])
# where,
# the index is the row position to insert a particular row
# [values] are the values to be inserted into the array.
# It must a list of values. It could be same length (5) as columns above
# Example:
# insert 5 new data at the third row
array.insert(2, [1,2,3,4,5])
#insert another column of data at the 6th row
array.insert(5, [8,9,10,11,12])
#display
print(array)
Output:
[[23, 45, 43, 23, 45], [45, 67, 54, 32, 45], [1, 2, 3, 4, 5], [89, 90, 87, 65, 44], [23, 45, 67, 32, 10], [8,9,10,11,12]]
using System;
using System.Linq;
using System.Runtime.InteropServices;
namespace ConsoleApplication4
{
public static class Program
{
private static void Main()
{
/*
C# supports multidimensional arrays up to 32 dimensions.
The multidimensional array can be declared by adding commas in the
square brackets.
For example, [,] declares two-dimensional array,
[, ,] declares three-dimensional array,
[, , ,] declares four-dimensional array, and so on.
So, in a multidimensional array, number of commas = Number of Dimensions.
*/
// For instance:
int[,] arr2d; // two-dimensional array
int[, ,] arr3d; // three-dimensional array
int[, , ,] arr4d ; // four-dimensional array
// declare and instantiate a 2d array with 4 rows and 5 columns
var array = new int[4,5]();
/* The [4, 5] defines the number of rows and columns.
The first rank (4) denotes the number of rows, and the second rank (5)
defines number of columns.
The code below instantiate and illustrate the 2d array divide into rows and columns.
*/
var array = new [,] // or var array = new int[4,5]
{
// col0,col1,col2,col3,col4
{0.1, 0.2, 0.3, 0.4, 0.5}, // row0
{1.1, 1.2, 1.3, 1.4, 1.5}, // row1
{2.1, 2.2, 2.3, 2.4, 2.5}, // row2
{3.1, 3.2, 3.3, 3.4, 3.5}, // row3
};
// Get the element 0.2 (that is row0, col1)
array[0, 1]; //returns 0.2
// Get the element 2.3 (that is row2, col2)
array[2, 2]; //returns 2.3
//array[4, 1]; //throws run-time error as there is no 4th row
//array[2, 5]; //throws run-time error as there is no 5th column
// get the third row
var row = array.GetRow(2);
// This prints 2.1, 2.2, 2.3, 2.4, 2.5
Console.WriteLine(string.Join(", ", row.Select(element => element.ToString())));
}
}
}