Hey,

Sorry if this has been asked before, I searched the forums, and couldn't find anyone with the same problem.

I am doing a simple comparison between two strings. If they do not equal each other, I want it to fire a function I wrote. It should be simple. Yet, my program always thinks the strings are not equal, even when they are.

I did a println of the two strings right before the comparison, and they both equal "p64". I thought maybe I perhaps had an accidental space being added to the end of one of the strings, so I checked their lengths, and they are both 3 characters long. They are absolutely identical in everyway that I can tell, yet processing never recognizes them as being equal, and always fires on the does not equal comparison.

Is this a processing bug, or I just completely missing something?

Thanks in advance for nay help.

-Thomas

What version of Processing are you using?  It might also help to include the code where you set the String variables to see what's happening at that end.

Curiously my test seems at odds with the documentation:

Code:

String foo = "p64";
String bar = "p64";

void setup() {
  size(100,100);
  if(foo == bar) {
    println("equal");
  }
  
  if(foo.equals(bar)){
    println("equal too");
  }
  
} 

From equals():

"This method is necessary because it's not possible to compare strings using the equality operator (==). "

That would suggest that there's some underlying reason why a standard comparison might not work; though when I run the above both conditions return true  

blindfish wrote on Dec 21^st, 2009, 2:28pm:


The compiler probably did some optimizations and detected that 2 different variables were in fact the same string and he probably used the same bit of memory for both variables.

This bit of code only prints the second equal:

Code:

String foo = "p64";
String bar = "p6";

void setup() {
  size(100,100);
  
  bar += "4";
  if(foo == bar) {
    println("equal");
  }
  
  if(foo.equals(bar)){
    println("equal too");
  }
  
}