‘this’ can’t be null
This is the first entry on a category I’d like to name “Code bloopers”. I recently got a message about a piece of code that was throwing a null pointer, it was basically of this form:
synchronized(this.foobar)
This is an easy one. If you think it’s because “this” is null, you have to go back to programming 101 and don’t collect $200 if you pass Go. I don’t want to sound mean, but yes, this is one of those bloopers that if you get it wrong, I hope it’s because you are half asleep or on drugs.
Remember kids, this can’t be null. In case you have been a victim of this code blooper, don’t feel bad, you are not the only one confused by this. It’s the only case (that I could find in the internet) of somebody else thinking this can be null, and I hope that gives you some comfort.
You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
class myclass1
{
public:
void setint( int _i )
{
if ( this != NULL )
{
if ( this->i != 17 )
{
i = _i;
}
}
};
private:
int i;
};
int main()
{
myclass1* pmyobject1; // = new myclass1;
pmyobject1 = NULL;
pmyobject1->setint( 17 );
delete pmyobject1;
return 0;
}