20181210.using.md

1. using

using (MemoryStream data1 = new MemoryStream())
using (MemoryStream data2 = new MemoryStream())
{
        // Lots of code..........
}
//同
using (MemoryStream data1 = new MemoryStream(), 
                    data2 = new MemoryStream())
{
    // do stuff
}
//同
using (MemoryStream data1 = new MemoryStream()) 
{
    using (MemoryStream data2 = new MemoryStream())
    {
        // Lots of code
    }
}

2. if/using/for，只有一行语句时，可以省略花括号，如

// Equivalent!
if (x==6) 
   str = "x is 6";

if(x == 6) {
   str = "x is 6";
}

// Equivalent!
for (int x = 0; x < 10; ++x) z.doStuff();

for (int x = 0; x < 10; ++x) {
   z.doStuff();
}

3. 假设语句后面只有一行，那么不使用花括号也可以。然而，人们忽略了，这一行可以是一个if/using/for与它自己的卷曲括号。下面是一个例子:

if(foo)
  if(bar)
  {
     doStuff();
  }