Break statement not working

This program should store the number of characters of name in the variable str_length (where name < 50 characters terminated by a ".") I'm baffled as to why thi开发者_如何学运维s code only spits out the first character, meaning it breaks from the loop when i = 0, for a name such as "Jonathan." Shouldn't it parse through the string until it finds the ".", only then breaking from the for loop?

#include <iostream>
#include <cstring>

using namespace std;

int main()
{

 string name;
 int str_length;

 cout << "What's your name" << endl;

 cin >> name;

 for (int i = 0; i < 50; i++)
 {
     cout << name[i];
     if (name[i] == '.')
        str_length = i;
        break;         
 }

 cout << endl;

 system("PAUSE");

 return 0;  
 }

---

You have:

for (int i = 0; i < 50; i++)
{
    cout << name[i];
    if (name[i] == '.')
       str_length = i;
       break;         
}

Which is actually:

for (int i = 0; i < 50; i++)
{
    cout << name[i];

    if (name[i] == '.')
    {
       str_length = i;
    }

    break;         
}

You want:

for (int i = 0; i < 50; i++)
{
    cout << name[i];
    if (name[i] == '.')
    {
       str_length = i;
       break;  
    }       
}

You are breaking at the end of each loop.

---

You are missing {} around if condition. So break is executed without any condition, hence the loop is exited in the first iteration itself.

---

This demonstrates the danger of not using braces even for one line if statements. I suspect you did this:

 if (name[i] == '.')
    str_length = i;

and then added the break later. If you had done this:

 if (name[i] == '.') { 
    str_length = i;
 }

up front, it would have been natural to add the break inside the curly braces, and you wouldn't have had the bug.