C++ Pointer Note
1 min readJul 3, 2022
- Pointer Introduction
#include <iostream>
using namespace std; int main(){
int n = 5;
cout << &n << endl; // print the memory location of int n int* ptr = &n; // create a pointer ptr points to n variable
cout << ptr << endl; // memory location
cout << *ptr <<endl; // 5 system("pause>0");
}
2. Change array size at runtime
Since array need to declare the size, ie myArray[3] = {5, 4}
, it is not allowed to change the size of the array. (Like the following example)
int main(){
int size;
cout << "Input the size of the array: " << endl;
cin >> size;
int myArray[size]
}
However, we can use “dynamic array” to change the size of the array at runtime:
int main(){
int size;
cout << "Input the size of the array: "<< endl;
cin >> size;
int* myArray = new int[size];
// print out the array
for (int i = 0; i < size; i++){
cout << "Array[" << i << "]: ";
cin >> myArray[i];
}
for (int i = 0; i < size; i++){
cout << myArray[i] << " ";
} delete[] myArray;
myArray = NULL;
system("pause>0");
}
Two things to be noted:
- Use
int* array_name = new int[size];
to create a dynamic array. - Once create the dynamic array, remember to delete using command
delete[] array_name