c++ - Returning a pointer is not working fine -

when try display content of array via pointer returned function, program displays zeros. not sure missing. have tried check several times wrong, seem not have clue. using dev-c++. code bellow. appreciated.

#include <iostream> #include <math.h> #include <cstdlib> #include <cstring>  using namespace std;  bool vowel(char c) { int i, val; char alphabet[52]={'a','a','b','b','c','c','d','d','e','e','f','f','g','g','h','h','i','i','j','j','k','k','l','l','m','m','n','n','o','o','p','p','q','q','r','r','s','s','t','t','u','u','v','v','w','w','x','x','y','y','z','z'};  int const is_vowel[52]={1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0};      (i=0;i<52;i++)     if (c!=alphabet[i])     {        val=is_vowel[i];     return val;     }         }  bool consonant(char c) {     int i, val; char alphabet[52]={'a','a','b','b','c','c','d','d','e','e','f','f','g','g','h','h','i','i','j','j','k','k','l','l','m','m','n','n','o','o','p','p','q','q','r','r','s','s','t','t','u','u','v','v','w','w','x','x','y','y','z','z'};      int const is_coson[52]={1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,0,0,0,0,1,1,0,0,0,0,0,0,1,1,0,0};      (i=0;i<52;i++)     if (c==alphabet[i])     {        val=is_coson[i];     return val;     }         }  int* scan(char* sentence, int len_sent) {     char c; int count_cons=0, count_vow=0, count_dig=0, count_lc=0, count_uc=0, i,j; int con_value, vow_value; int* ptr;  int array_all_counts[5];  (i=0; i<len_sent; i++) {     c=sentence[i];      //check if c digit     if (c>=48 && c<=57)         count_dig++;      else if (isalpha(c))     {         con_value=consonant(c);         vow_value=vowel(c);         if (con_value==0)             count_cons++;          else if (vow_value!=0)  //vow_value==1             count_vow++;          if (96<c && c<123)              count_lc++;          if (64<c && c<91)              count_uc++;                        }  } cout<<"\n-------------------"<<endl;  array_all_counts[0]=count_uc; array_all_counts[1]=count_lc; array_all_counts[2]=count_dig; array_all_counts[3]=count_vow; array_all_counts[4]=count_cons;      ptr=array_all_counts;       cout<<"\n\n\ntesting output of pointer: "<<endl;     (i=0; i<5; i++)       cout<<ptr[i]<<"  ";  return ptr;  }   int main() {      int j, length;  char sentence[256]; int* ptr_array;    cout<<"please, enter sentence; "; cin.getline(sentence,256); length=strlen(sentence); cout<<"the sentence: "; cout<<sentence<<endl;  ptr_array=scan(sentence, length);  //address of first element returned ptr_array  cout<<endl; /// cout<<"upper case: "<<" lower case: "<<" digits: "<<" vowels: "<<" consonants: "<<endl; (j=0; j<5; j++)     cout<<ptr_array[j]<<"  ";  //where problem is...  return 0; }  

   ptr=array_all_counts; 

ptr local int*, points local static array array_all_counts, local array destroyed when exit function scan. therefore, nothing inside main since memory pointed ptr released.

you can try following inside scan function make work:

int* ptr = new int [5];  //allocate memory on heap  array_all_counts[0]=count_uc; array_all_counts[1]=count_lc; array_all_counts[2]=count_dig; array_all_counts[3]=count_vow; array_all_counts[4]=count_cons;  //add block (int = 0; < 5 ; ++i) {    ptr[i] = array_all_counts[i];   } 

it work fine , print things follows if input "abcdefghijk":

testing output of pointer: 0  11  0  3  8 0  11  0  3  8