C # Basic Learning (0701) Some simple ways to practice

A simple way to find the maximum value of an array

Variable parameters

int max= Getmaxnumbers (101,30)

Static int Getmaxnumbers (paramsint[] PMs) {  int max=pms[0];    for (int i=1; I<pms. length;i++)  {    if(pms[i]>max)    {      max=pms[i];    }  }   return Max;}

An easy way to calculate the 1-100 and

Static int getsum () {  int result=0;    for (int i=1; i<=; i++)  {    result=result+i;  }   return result;}

Calculates 1-100 between all odd and

Private Static int getoddsum () {  int sum=0;    for (int i=1; i<=; i++)  {    if(i%2! =0)      {+ =i;    }  }
  return sum;}

Determines whether a given integer is a "prime"

Private Static BOOL Iszhishu (int number ) {  for (int i=2;i<number;i++)  {     if (number%i==0)    {      returnfalse;    }  }   return true ;}

Calculates the number of all prime numbers between 1-100 and (applies to the above function of judging prime numbers)

Private Static int getzhishusum () {  int sum=0;    for (int i=2; i<=; i++)  {    if(Iszhishu (i))    {      sum+ =i;    }  }   return sum;}

Suppose you have a string array that uses the method to output the longest string

Private Static string Getmaxname (string[] names) {  string maxname=names[0];    for (int i=1; i<names. length;i++)  {    if(Names[i]. length>maxname.length)    {      Maxname=names[i];    }  }   return Maxname;}

Several ways of declaring a string array

int [] arr=newint[ten];
int [] arr1=newint[]{, a-ten;

Int[] arr2=new int[3]{10,20,30};

int [] arr3={One,a.

Calculates the average of an integer array

int[] arrint={1,3,5,7, -, -,Wuyi, -};Doubleavg=Getavg (arrint);Private Static DoubleGetavg () {Doublesum=0;  for(intI=0; i<arrint.length;i++) {sum+=Arrint[i]; }  returnMath.Round (sum/(Double) arrint.length,2);//result reserved two decimal places (rounded)}

Sort an array of integers in ascending order by bubbling Sort method

int[] arrint={1,3,5,7, -,2,4,6,8,Ten}; for(intI=0; i<arrint.length-1; i++){   for(intj=arrint.length-1; j>i;j--)  {    if(arrint[j]<arrint[j-1])    {      //from back to front 22 contrast, small put forward      inttmp=Arrint[j]; ARRINT[J]=arrint[j-1]; Arrint[j-1]=tmp; }  }} for(intm=0; n<arrint.length;n++) {Console.WriteLine (Arrint[n]);} Console.readkey ();

Counts the number of occurrences of a specified character in a string

//The IndexOf () method reports the index of the first occurrence of the specified string in this instance (returns 1 if the found character has no item-matching value)//The LastIndexOf () method report specifies that only the index of the last occurrence in this instance is obeyedstringmsg="is just against the open hanging Identity classic style style third planning Republicans and spec don't let go over there functional place";//0 indicates that the index starts at the first character position//Msg. IndexOf ("The", 0)//number of occurrences of the record "intCount=0;intindex=0; while(Index=msg. IndexOf ("of the", index))!=-1)//while the condition is that the value returned when the lookup is not-1{Count++; Console.WriteLine ("{0} occurrences of "" at index location: {1}", Count,index); Index=index+"of the". Length;} Console.WriteLine ("" of" has appeared {0} times in total", Count); Console.readkey ();//count the occurrences of each characterdictionary<Char,int> dict=Newdictionary<Char,int>(); for(intI=0; i<msg. length;i++){  if(!Dict. ContainsKey (Msg[i])) {Dict. ADD (Msg[i],1); }  Else{Dict[msg[i]]++; }}foreach(keyvaluepair<Char,int> Iteminchdict) {Console.WriteLine ("the character {0} appears {1} times", item. Key,item. Value);}

Remove both ends of the string and replace all other spaces in it with a single space

stringmsg="Hello World , you are in season! ";//Trim () method to remove both spaces//split with split method, stringsplitoptions.removeemptyentries remove Spacemsg=Msg. Trim ();string[] words=msg. Split (New Char[] {' '},stringsplitoptions.removeemptyentries); msg=string. Join (" ", words); Console.WriteLine ("===="+msg+"===="); Console.readkey ();

C # Basic Learning (0701) Some simple ways to practice