c - Assignment of a value, followed by comparison in "if" statement's condition in C

Question

I want to write some code with the following logic. From a clarity and conciseness point of view, is the first approach better than the other two?

if(kErrNone != (cs_error = get_last_error(component)))
{
    /* Do something. */
}


if((cs_error = get_last_error(component)) != kErrNone)
{
    /* Do something. */
}


cs_error = get_last_error(component);
if(cs_error != kErrNone)
{
    /* Do something. */
}

Answer 1

对我来说，这是第三个。因为条件更容易评估。

Answer 2

从简洁的角度来看，前两个if块明显优于第三个。

实际上，第一个if和第二个if之间没有显着差异，因为您只是更改了比较表达式的两侧。

第三个不必要地添加了一个语句，因为对cs_error的赋值可以巧妙地组合到if块中。但是，是的，如果您对牙套不小心，就有可能出错。