Sandbox/IfAndSwitchInitStatements.cpp

   1 #include "IfAndSwitchInitStatements.h"
   2
   3 #include <iostream>
   4 #include <vector>
   5 #include <algorithm>
   6 using namespace std;
   7
   8 // Ep 21: https://www.youtube.com/watch?v=AiXU5EuLZgc
   9
  10 namespace IfAndSwitchInitStatements
  11 {
  12     vector<int> make_vec()
  13     {
  14         return { 1, 2, 3, 4 };
  15     }
  16 }
  17
  18 void IfAndSwitchInitStatements::tests()
  19 {
  20     auto vec = make_vec();
  21
  22     // Same for 'switch' block.
  23     if (const auto itr = find(vec.begin(), vec.end(), 2);
  24         itr != vec.end())
  25     {
  26         *itr = 42;
  27     }
  28     else
  29     {
  30         vec.push_back(42);
  31     }
  32
  33     // Declare an variable into a if condition allows to use this variable only in the if scope
  34     // and will not get out of scope.
  35     // Here we can reuse the name 'itr' previously used in the previous if statement.
  36     if (const auto itr = find(vec.begin(), vec.end(), 3);
  37         itr != vec.end())
  38     {
  39         *itr = 43;
  40     }
  41     else
  42     {
  43         vec.push_back(43);
  44     }
  45
  46     for (auto i = vec.begin(); i != vec.end(); ++i)
  47     {
  48         if (i != vec.begin())
  49             cout << ", ";
  50         cout << *i;
  51     }
  52
  53     cout << endl;
  54 }