allocate memory dynamically

hi, i was learning to allocate memory dynamically as and when needed.my 2 codes got errors.

Code:

---

int main(void){
        int *a;
        int i=0;
        for(i=0;i<10;i++){
                a=new int[1];
                a[i]=i;
        }
}

---

Code:

---

        char *a;
        a=new char[1];
        a="a";

        a=new char[1];
        a++;
        a="t";

        cout<<a;  /*expecting a output of at:but only get output of t*/

---

if some one can correct my errors,its helpfully enough.

Well the first one should have
a = new int[10];
outside the loop, and only the assignment inside the loop

As for the second, look up strcpy, and don't increment 'a', otherwise you'll never know what to delete later on.

You need to allocate an array all at once, in a single new statement. Otherwise the memory isn't contiguous. For example your first code snippet should be

Code:

---

int main() {
  int *a;
  int i=0;
  a = new int[10];
  for (i=0; i<10; i++) {
    a[i] = i;
  }
}

---

Hopefully you already know how to use string and vector, which are generally better choices in C++ than dynamically allocating an array.