. NET Learning Notes----2015-06-25 (Practice for generic collections)

1: Put an odd number in one array into a collection, then put an even number in another collection, and eventually merge the two collections into a single collection, and the odd numbers appear on the left and the even to the right.

Ideas:

(1) Determining the parity of elements in an array, assigning values to 2 sets, respectively

(2) Declaring the third set, passing in the odd and even 2 sets separately | | Add another collection directly with one of the collections

Question: How to Output: "Odd: 1,3,5,7 | Even: 2,4,6,8 "?

            int[] Nums = {1,2,3,4,5,6,7,8,9 }; List<int> Jishu =Newlist<int>(); List<int> Oushu =Newlist<int>(); //list<int> all = new list<int> ();             for(inti =0; I < Nums. Length-1; i++)            {                if(Nums[i]%2!=0)//Odd{jishu.add (nums[i]); }                Else//even{oushu.add (nums[i]);            }} jishu.addrange (Oushu); foreach(varIteminchJishu) {Console.Write (item+" "); } console.readkey ();

2: Prompts the user to enter a string to assign the user-entered string to a character array through a foreach loop

Ideas:

Receives the user input directly with a string, and then assigns each element in the string to a character array through a foreach

Console.WriteLine ("Please feel free to enter"); stringstr =Console.ReadLine (); Char[] CHS =New Char[Str.            Length]; inti =0; foreach(varIteminchstr) {Chs[i]=item; I++; }            foreach(varIteminchCHS) {Console.Write (item+" "); } console.readkey ();

3: Count the number of occurrences of each character in welcome to, regardless of case

Ideas:

Number of characters---> occurrences

Key-----> value

Put each character in the string as a key into the key value pair set, and put the number of occurrences of each character in the value of the key value pair.

            stringstr ="Welcome to China"; Dictionary<Char,int> dic =Newdictionary<Char,int>();  for(inti =0; I < Str. Length; i++)            {                if(Str[i] = =' ')                {                    Continue; }                //if DIC already contains the key that is currently circulating, the value of this key is +1                if(DIC. ContainsKey (Str[i])) {//value +1dic[str[i]]++; }                Else//this character appears in the collection for the first time.{Dic[str[i]]=1; }            }            foreach(keyvaluepair<Char,int> KVinchdic) {Console.WriteLine ("the letter {0} appeared {1} times", KV. Key, KV.            Value); } console.readkey ();

. NET Learning Notes----2015-06-25 (Practice for generic collections)