循环时非终止

我只是想知道一些事情。我有以下代码：

#include <iostream>
using namespace std;
int main()
{
    int number, largest, counter = 1;
    while (counter <= 10)
    {
          cout << "Enter a number: ";
          cin >> number;
          if (counter = 1)
          {
               largest = number;
          }
          else if (number > largest)
          {
               largest = number;
              }
          counter++;
    }
    cout << "nnThe largest number is: " << largest;
    system("pause");
    return 0;
} 

问题是，它永远不会终止。我确实设法通过稍微修改代码来解决问题，但我想知道为什么会发生这种情况。这是固定代码：

#include <iostream>
using namespace std;
int main()
{
    int number, largest, counter = 1;
    cout << "Enter a number: ";
    cin >> number;
    largest = number;
    while (counter < 10)
    {
      cout << "Enter a number: ";
      cin >> number;
      if (number > largest)
      {
           largest = number;
      }
      counter++;
    }
    cout << "nnThe largest number is: " << largest << endl;
    system("pause");
    return 0;
}

似乎在删除 else if 语句后它起作用了。发生了什么事？