For loops: How does c++ know when they end?

[bustaballs]

I'm working my way through "Beginning C++ Through Game Programming Second Edition" and on chapter 3, I'm introduced to "for" loops. The example code is as follows:

// Counter
// Demonstrates for loops

#include <iostream>

using namespace std;

int main()
{
    cout << "Counting forward:\n";
    for (int i = 0; i < 10; ++i)
        cout << i << " ";

    cout << "\n\nCounting backward:\n";
    for (int i = 9; i >= 0; --i)
        cout << i << " ";

    cout << "\n\nCounting by fives:\n";
    for (int i = 0; i <= 50; i += 5)
        cout << i << " ";

    cout << "\n\nCounting with null statements:\n";
    int count = 0;
    for ( ; count < 10; )
    {
        cout << count << " ";
        ++count;
    }

    cout << "\n\nCounting with nested for loops:\n";
    const int ROWS = 5;
    const int COLUMNS = 3;
    for (int i = 0; i < ROWS; ++i)
    {
        for (int j = 0; j < COLUMNS; ++j)
            cout << i << "," << j << "  ";
        cout << endl;
    }

 return 0;
}

While I understand what the code does, I don't understand how c++ knows when the loop code is supposed to end. In Visual Basic, there was always something specifying the end of a loop. With "while" and "do" loops in c++ there are squiggle brackets enclosing the loop. To me, much of this looks like loops inside of loops. Is it because the other ones only have a single line of code following them that they don't have to be enclosed in squiggle brackets?

[tummychow]

The condition is what controls the loop.
for (initialization ; condition ; update)
The idea is that in a for loop, the loop is controlled by a counter, so it will run a determinate, finite number of times. The counter is, traditionally, increased after every execution of the loop. Once the condition is false, the loop ends and the code moves on.
for (int i = 0; i < 7; i++)
That for loop would run 7 times. After running for i = 6, it would be incremented to seven and seven is not less than seven. So the loop would end. All loops in C++ are condition driven.
Also note the difference between a regular bracket and a curly brace. Curly brackets denote scope and code block. Normal brackets are for calling functions and storing conditions.
Read this:
http://www.cplusplus.com/doc/tutorial/control/
EDIT: By the way... those single line loops? Those are always allowed. If, after a control structure statement (exception being switch, I believe), you only have one statement, you can skip the curly brackets. That includes all loops and the if/else if/else structures.

while (true)
    cout << "Annoyed yet?"; // totally legal 

EDIT 2: (Wow this site is lagging today) Also denote the difference between a line and a statement.
cout << "hey"; cout << " this"; cout << " is"; cout << " bad"; cout << " style";
All that is five statements. You could cram the entirety of main onto one line and as long as you had the semicolons in their proper places, C++ doesn't care about the leading whitespace. This would even work, I think:
cout << "even";cout << " worse";cout << " style";

[Disch]

if, else, while, for, etc all have the same pattern. They execute the next statement (up to the next semicolon) or the next code block (the next set of {braces})

// this example has no braces
//  it will go to the next semicolon:

if(something)
  Foo();

Bar();  // this is not part of the above 'if'.  The 'if' stops at the semicolon after Foo() 

// this example has braces
//  it will go through the code block:

if(something)
{
  Foo();

  Bar();  // now, this IS part of the 'if' because it is inside the braces
}

Baz();  // but this is outside, so it's not part of the 'if' 

// this example is perfectly legal syntax and will compile okay, but
//  is probably a mistake

if(something);
{
  Foo();  // this is not part of the if!
}

// notice that there's a semicolon after the if.  Therefore the if stops immediately (it effectively has nothing in it)
//  therefore Foo() is not part of the if because the if has already ended 

[bustaballs]

Ah, I didn't know you could put multiple statements on the same line which is why I mentioned line instead of statement. I guess no one does that very often for the sake of clean code.

Question answered. Thank you very much.