Answers for "array length c++ for loop"

array length c++

#include <iostream>
using namespace std;

#define size(type) ((char *)(&type+1)-(char*)(&type))

int main(){
  int arr[5] = {1, 2, 3, 4, 5};
  cout << size(arr) / size(arr[0]) << endl; //returns 5
  //alternatively
  cout << sizeof(arr) / sizeof(int) << endl; //returns 5
}

lopping over an array c++

for (int i = 0; i < arr.size(); ++i){
//use if we explicitly need the value of i
cout << i << ":\t" << arr[i] << endl;
}
for (int element : arr){
//modifying element will not affect the array
cout << element << endl;
}
for (int &element : arr){
//modifying element will affect the array
cout << element << endl;
}

for loop with array c++

int v[] = {1,2,3,4,5};
for (int n : v)
  cout << n << endl;
//make sure to compile with -std=c++11