what happens with if == statement with no arguments?-CodePudding

With

if (i==1) {something} - program will execute something on true

what happens with

if (i==1) - will it break or do nothing on false?

I've seen program with

if (id == 0x11) //OK

with no {} and don't know if it does something. I think it should use next line as its "insides" but it wouldn't change anything

CodePudding user response：

The next statement will be used as the if block. Opening brace does not necessarily be on the same line with the if, and a single statement if does not need to use opening and closing braces. All of the following are equivalent:

if (expression) // OK
{
    statement1;
}

if (expression) { statement1;}

if (expression)
    statement1;

CodePudding user response：

The syntax is (C11 6.8.4)

if (<condition>) <statement>

where <condition> is some expression with a value compatible to int
and
<statement> is a regular statement or a block statement.

if (foo == 42) return 4; // regular statement ends with semicolon
if (bar == foo) { puts("nope!"); exit(EXIT_FAILURE); } // block statement

And, remember that whitespace is not significant in C text source

if (a == b)

b = 0;

is equal to

if (a == b) b = 0;

CodePudding user response：

If condition was false statements with in if condition were not executed..