In my answer here: C# Lock syntax - 2 questions, LukeH pointed out that try...catch...(finally) statements require curly braces.
I found the answers as to why, found here ( Why do try..catch blocks require braces? ) very interesting.
I'd like to know of any more examples where curly braces are required as opposed to good practice etc, ideally with code snippet and explanation as to why.
Around a method body.
// not allowed:
int Inc(int x)
return x+1;
The why is not so easy, it would seem old-style C needed it more than C++/C#.
A little more about the why part, in (very) old C you would write
int Sum()
int a, b; // parameters, very informal
{
int s; // local var
...
}
So this ancient syntax needed the braces. And in all the languages that are based on C, nobody ever saw a point in making them optional, assuming that was possible in some cases.
You must use either braces or parentheses with checked and unchecked, depending on whether you're treating them as operators or statements:
// legal operator
int y = checked(x * 2);
// legal statement
unchecked
{
if ((a * b) > c)
{
DoSomething();
}
}
// illegal operator
int y = checked x * 2;
// illegal statement
unchecked
if ((a * b) > c)
DoSomething();
Certain parts of language require braces to be present. For example, when you start a method you have to open and close braces to identify that as a code block. Inside a function certain language features like loops, conditinal statements, etc. also accept braces although in some cases they are not required. For example:
if (someValue == true)
doSomething();
In this case braces are not required, however you can surround this statement with braces, because you have just one statement that will be executed after if check, but if you want to execute multiple statement inside an if you need to use braces. For example,
if (someValue == true)
{
doSomething();
doSomeMoreWork();
}
Trying something like this is not allowed:
if (someValue == true)
doSomething();
doSomeMore();
else
doWork2();
int i = 1 + 2;
Compiler will complain in this case.
The problem can best be seen in the following loop:
while(i < 10)
doSomeWork();
i++;
Here you would expect i to increment, but this never happens. Basically this loop is the same as this one:
while(i < 10)
{
doSomeWork();
}
i++;
The statement inside the block will execute infinetly and i will never increment. In that case the proper way to write this statement would be:
while(i < 10)
{
doSomeWork();
i++;
}
Now you have a properly working statement. I like to use braces all the time regardless of number of statements that are being executed. The reason for this is that sooner or later I might need to add some more work in my if statement or inside a for or foreach loops. It's just a good practice.
class/struct/interface declaration
class X { int _myval }
