C # Getting Started 2-arrays and collections

Foreword: The array and the collection can put many kinds of data together, greatly simplifies the development process of the program, after a week of learning, is now an array of groups and sets are summarized as follows:

1. Array and set comparison analysis:

Category: Array collection
Length: fixed length indefinite length
Memory: Consumes less memory
The reciprocal conversion of an array must be able to be transformed into a set, whereas the other is not necessarily
Declaration: Data type [] variable name list< data type > variable name;
Assignment: Variable name =new data type
[length]; variable name =new list< data type > ()
READ: variable name. Lenght; variable name. Count;
Modify: Variable name [index]= value; variable name [index]= value;
Initializer: New data type [] {data Value ...} Variable name =new list< data type > () {data value};
To add an element:

Because of the fixed length of the array, solid cannot change the name of the original array length variable. Add (the data to be added);
Insert element: variable name. Insert (index, new data)
Delete element: variable name. RemoveAt (index);
The variable name. Remove (data);

2. Arrays:
Example: Create an array of type int, the variable name is nums, and use the initializer to assign a value to each of its items (optionally assigning some value), let the user enter a subscript and a new number, modify the array corresponding to the subscript of the number, if the subscript out of range, to give the error prompt, and let the user re-enter, The largest number in the output array

int [] Nums=new int[5]{5,8,10,6,7}
Console.Write ("Please enter a subscript")
int Index=int. Parse (Console.ReadLine ());
while (Index < 0 | | index > MAXINDEX)
{
Console.Write ("Input error, please re-enter:");
index = Int. Parse (Console.ReadLine ());
}
Console.Write ("Please enter a new number:");
int newnumber = Int. Parse (Console.ReadLine ());
Nums[index] = Newnumber;
Console.WriteLine;

int max = nums[0];
for (int i = 1; i < Nums. Length; i++)
{
if (Nums[i] > Max)
{
Max = nums[i];//Save this larger number to Max
}
}
Console.WriteLine ("Max number:" + max);

3. Collection:
Example: Using a collection initializer, initializing a collection of type int, then deleting the first item of the collection, adding a number 2 to the first item of the collection, prompting the user to enter 3 numbers, then loading the 3 numbers sequentially into the collection, and finally outputting the contents of the collection

list<int> nums = new List<int> () {3, 6, 8, 2, 1};
Nums. RemoveAt (0);
Nums. Insert (0, 2);

list<int> nums = new list<int> ();
Console.Write ("Please enter the 1th number:");
Nums. ADD (int. Parse (Console.ReadLine ()));
Console.Write ("Please enter the 2nd number:");
Nums. ADD (int. Parse (Console.ReadLine ()));
Console.Write ("Please enter the 3rd number:");
Nums. ADD (int. Parse (Console.ReadLine ()));
for (int i = 0; i < Nums. Count; i++)
{
Console.Write (Nums[i] + "");
}

C # Getting Started 2-arrays and collections