syntax for using "Not if" statement

Question

Is this syntactically correct.

success: function(results) {         
            if (results.d.Name.length > 1) {       
               if (!(results.d.Id > 0)){      
                  results.d.Id = 0;    
               }
               var html = '<img style="float:left; height:100px;" src="inc/images/'
               + results.d.Id + '.gif" />' 
               // more code;
            }
         }

OK the reason I am wanting a zero is because if the id=1235344 is not assigned I need to show the 0.gif (default image). How can I achieve this.

Answer 1

If it works, yes. If it does not, no.

Answer 2

sound ok to me!

Answer 3

Wouldn't the opposite of a greater than (>) be less than (<)?

So instead of:

if (!results.d.Id > 0)

Try:

if (results.d.Id < 0)

---

Per your comment: Then just do this:

if (!results.d.Id)
    results.d.Id = 0;

The ! operator returns false if the variable is either false, null, undefined, 0, or an empty string. An even simpler way to do it would be this:

results.d.Id = results.d.Id || 0;

If the ID has already been set (and is non-zero), then keep it, else set it to zero. This way you don't even need an if statement. So your end result would look something like this:

success: function(results) {         
    if (results.d.Name.length > 1) {       
        results.d.Id = results.d.Id || 0;
        // more code;
    }
}

Answer 4

According to this, the ! (not) operator is executed before the > (comparison).

replace this

            if (!results.d.Id > 0) {

with this

            if (!(results.d.Id > 0)) {

Answer 5

The closing braces are missing, and I added ( and ) in your condition

success: function(results) {
    if (results.d.Name.length > 1) {
        if (!(results.d.Id > 0)) {
            results.d.Id = 0;
        }
        //more code;
    }
}