Which is clearer form: if(!value) or if(flag == value)?

Question

I understand this is a subjective question, so I apologize if it needs to be closed, but I feel like it comes up often enough for me to wonder if there is a general preferen

Answer 1

I favour the if (!value) style at least for evaluating variables or common properties like Page.IsPostback and the like. For anything more complex I tend to parenthesise the expression like thus:

if (!(SomeType.SomeProperty.CallingAMethod(input).GetSomething.BooleanProperty))

Just to draw a little more attention to it.

All in all, it's an argument for Perl-style unless and until keywords.

Answer 2

I use Not value when coding in VB but tend to use value == false when coding in C#. I find that the exclamation point can sometimes be lost in the name of the variable (e.g. !legal). Maybe it's because I'm, uh, a seasoned veteran.

Answer 3

I am also of the opinion that using == inside an if is redundant and I have another suggestion, at least visually, by introducing spaces:

if ( ! created)

Even using OpenDyslexic as font, the not sign ! next to the opening bracket ( can be too close to distinguish it at a glance if(!created).

Answer 4

I actually many of forms possible.

This is not actually how it is written to standards, but this is how I see it:

//if foo is(or exists)
if(foo)

//if foo is true
if(foo == true)

//if foo doesn’t exist
if(!foo)

if foo is false
if(foo == false)

Hence I don’t see == false is redundant.

Answer 5

I use if (value == false) The ! in if (!value) is so small I sometimes miss it.

Answer 6

If the condition is just a check of a single value, then !value is quicker.

However, when the condition contains multiple value checks, I find it much easier to read value == false. Somehow it is easier to parse multiple checks for equality than multiple negations of values.