c++ - Sorting an array that has been user generated has garbage data -

i have program user inputs 50 integers. allows user search integer, shows in array once sorted, , mean of elements.

where i'm stuck is, user generated input is...wrong. when print out array, it's incorrect values.

the code:

//inputsearch.cpp  //this program allow user enter 50 integers.  //it allow user search array created.  #include<iostream> using namespace std;  const int size = 50;  void displayarray(int[],int);       // protoype print out array   void sortarray(int [], int);        // prototype sort array function int binarysearch(int[], int, int);  // prototype binary search function int getaverage(int[], int);         // prototype average of array  int main() {    int arraylist[size];    //array...    int searchfor=0;        // we're gonna search    int found;     int pos = 0;     cout << "please enter 50 integers (or -99 stop): \n" ;    cin  >> arraylist[pos];                                             // puts integers in array     while (arraylist[pos] != -99)                                       // -99 stop otherwise we'll here day    {       pos++;       cout << "\nplease input 50 integers (or -99 stop)\n";       cin >> arraylist[pos];     }     int value=pos;      //how many elements entered     sortarray(arraylist, size);     // sorts array     cout << "enter integer search for: ";    cin >> searchfor;     found = binarysearch(arraylist, size, searchfor);      if (found == -1)       cout << "the value " << searchfor << " not in list" << endl;    else    {       cout << "the value " << searchfor << " in position number "          << found + 1 << " of list" << endl;     }      cout << "\n\n";    displayarray(arraylist,value);     cout << "\n\n";    cout << "the mean of values of array is: " << getaverage(arraylist, value);    cout << "\n\n";    cout << "\n\n array has " << value << " inputted elements\n\n";    return 0; }  void sortarray(int array[], int elems) {    bool swap;    int temp;    int bottom = elems - 1;              {       swap = false;       (int count = 0; count < bottom; count++)       {          if (array[count] > array[count+1])          {             // next 3 lines swap                temp = array[count];               array[count] = array[count+1];             array[count+1] = temp;             swap = true; // indicates swap occurred          }       }       bottom--;     // bottom decremented 1 since each pass through       // array adds 1 more value set in order     }while(swap != false);    // loop repeats until pass through array    // no swaps occurs }  int binarysearch(int array[],int numelems,int value) //function heading {    int first = 0;                  // first element of list    int last = numelems - 1;        // last element of list    int middle;                    // variable containing current     // middle value of list     while (first <= last)    {       middle = (first + last) / 2;         if (array[middle] == value)          return middle;             // if value in middle, done        else if (array[middle]>value)          last = middle - 1;         // toss out second remaining half of       // array , search first        else          first = middle + 1;        // toss out first remaining half of       // array , search second    }     return -1;                     // indicates value not in array }  void displayarray(int array[], int elems)     {    (int count = 0; count < elems; count++)    {       cout << array[count] << "  " << endl;    } }  int getaverage (int array[], int size) {      int sum = 0;   // holds sum of numbers     (int pos = 0; pos < size; pos++)       sum = sum + array[pos];  // sum holds sum plus next element     return (sum / size);  //returns average } 

the ouput entering 100 , 100:

please enter 50 integers (or -99 stop):
100

please input 50 integers (or -99 stop)
100

please input 50 integers (or -99 stop)
-99
enter integer search for: 100
value 100 in position number 36 of list

-99

-1

the mean of values of array is: -50

the array has 2 input elements

---

any appreciated.

you seeing strange behavior due following problems:

1. you haven't initialized array arraylist.
2. you sorting entire array instead of sorting number of entries user entered.
3. you using entire array search.

by changing

sortarray(arraylist, size);     // sorts array 

to

sortarray(arraylist, value);     // sorts array 

and

found = binarysearch(arraylist, size, searchfor);  

to

found = binarysearch(arraylist, value, searchfor);  

you able solve problems.

you can use initialize array using:

int arraylist[size] = {0}; 

that won't change how program works once fix use of sortarray , binarysearch.