How do I check whether the object q1 exists? ie: q1=new queue has been called?

wc3promet · #1 15-Oct-2004, 10:07

How do I check whether the object q1 exists? ie: q1=new queue has been called?

In Main

CPP / C++ / C Code:

queue* q1;

Partial Body of Menu Code

CPP / C++ / C Code:

  	case 1:
	 cout<<"\n";
 	q1 = new queue;
 	break;

Partial Body of Enqueue Code

CPP / C++ / C Code:

str name;
name = "Some Name"
q1->enqueue(name);

Because if I call the enqueue(), the program is going to crash. Testing whether q1==NULL doesn't seem to help.

Any suggestions? Thanks.

dsmith · #2 15-Oct-2004, 10:15

Hi. Why don't you set it to NULL when you define it?

CPP / C++ / C Code:

queue* q1 = NULL;

That should point the pointer to 0 (undefined). Then you should be able to test whether it is there by:

CPP / C++ / C Code:

if(q1){
}

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