我必须承认，我并不总是在单行中使用{}，但这是一种很好的练习。

假设你写的代码没有括号，看起来像这样: For (int I = 0;I < 100;+ + i) For (int j = 0;J < 100;+ + j) DoSingleStuff ();

过了一段时间，你想在j循环中添加一些其他东西，你只是通过对齐来做，忘记添加括号。

Memory deallocation is faster. Let’s say you have a big scope and create big arrays inside (without new so they are on the stack). Those arrays are removed from memory just after you leave the scope. But it is possible that you use that array in one place and it will be on the stack for a while and be some kind of rubbish. As a stack have limited and quite small size, it is possible to exceed the stack size. So in some cases it is better to write {} to preventing that. Note that this is not for a single line, but for such situations: if (...) { //SomeStuff... {//we have no if, while, etc. //SomeOtherStuff } //SomeMoreStuff } The third way to use is similar to the second. It is just not to make the stack cleaner, but to open some functions. If you use mutex in long functions usually it is better to lock and unlock just before accessing data and just after finishing reading/writing that. Note: This way is used if you have some of your own class or struct with a constructor and destructor to lock memory. What is more: if (...) if (...) SomeStuff(); else SomeOtherStuff(); // Goes to the second if, but alignment shows it is on first...

总而言之，我不能说，总是使用{}的最佳方式是单行，但这样做并没有什么不好。

如果你编写的是编译代码，但是如果你的代码是被解释的，那么你的代码就会非常非常慢。非常轻微。

帮助防止在前面的回答中描述的错误的一个选项是内联您希望在不使用大括号时发生的事情。当您尝试修改代码时，很难不注意到错误。

if (condition) doSomething();
else doSomethingElse();

if (condition) doSomething();
    doSomething2(); // Looks pretty obviously wrong
else // doSomethingElse(); also looks pretty obviously wrong

如果不使用{和}，很容易意外地用注释更改控制流。例如:

if (condition)
  do_something();
else
  do_something_else();

must_always_do_this();

如果你用一行注释注释掉do_something_else()，你会得到这样的结果:

if (condition)
  do_something();
else
  //do_something_else();

must_always_do_this();

它会编译，但must_always_do_this()并不总是被调用。

我们在代码库中遇到了这个问题，有人在发布之前很快地禁用了一些功能。幸运的是，我们在代码审查中发现了它。

它通过清楚地定义循环和条件块的范围，使您的代码更具可读性。它还可以避免你意外出错。

我认为第一个比第二个更清楚。它给人一种结束指令的感觉。使用短代码是可以的，但是当代码变得复杂时，{…}帮助很大，即使它是endif或begin…end。

// First
int j = 0;
for (int i = 0 ; i < 100 ; ++i)
{
    if (i % 2 == 0)
    {
        j++;
    }
}


// Second
int j = 0;
for (int i = 0 ; i < 100 ; ++i)
    if (i % 2 == 0)
        j++;
i++;

我必须承认，我并不总是在单行中使用{}，但这是一种很好的练习。

假设你写的代码没有括号，看起来像这样: For (int I = 0;I < 100;+ + i) For (int j = 0;J < 100;+ + j) DoSingleStuff ();

过了一段时间，你想在j循环中添加一些其他东西，你只是通过对齐来做，忘记添加括号。

Memory deallocation is faster. Let’s say you have a big scope and create big arrays inside (without new so they are on the stack). Those arrays are removed from memory just after you leave the scope. But it is possible that you use that array in one place and it will be on the stack for a while and be some kind of rubbish. As a stack have limited and quite small size, it is possible to exceed the stack size. So in some cases it is better to write {} to preventing that. Note that this is not for a single line, but for such situations: if (...) { //SomeStuff... {//we have no if, while, etc. //SomeOtherStuff } //SomeMoreStuff } The third way to use is similar to the second. It is just not to make the stack cleaner, but to open some functions. If you use mutex in long functions usually it is better to lock and unlock just before accessing data and just after finishing reading/writing that. Note: This way is used if you have some of your own class or struct with a constructor and destructor to lock memory. What is more: if (...) if (...) SomeStuff(); else SomeOtherStuff(); // Goes to the second if, but alignment shows it is on first...

总而言之，我不能说，总是使用{}的最佳方式是单行，但这样做并没有什么不好。

如果你编写的是编译代码，但是如果你的代码是被解释的，那么你的代码就会非常非常慢。非常轻微。