need help with if statement in loop

[Snackers]

Apparently I don't understand conditional statements. I have a loop, and in the first iteration I need something to happen. The statement in my if (i==0) never executes. Basically I want to create a new ImageStack when the first image in the loop is loaded. Can some one tell me what I am doing wrong here?

		for (int i=0; i<files.length; i++) {
			ImagePlus img = opener.openImage(path, files[i].getName());
			if (i==0) {
                ImageStack stack = new ImageStack(img.getWidth(), img.getHeight(), 2);
			}

			if (img!=null) {
				img.show();
                stack.addSlice(files[i].getName(),img.getProcessor().getPixels());
                }
		}

Edited: I guess I should add my error message when I compile:

C:\Program Files (x86)\ImageJ\plugins\Gallery_File_Opener.java:61: cannot find symbol
symbol : variable stack
location: class Gallery_File_Opener
stack.addSlice(files[i].getName(),img.getProcessor().getPixels());
^
1 error

[JosAH]

The variable 'stack' is local to that first if-statement body; define it before line #3 and it still exists in the second if-statement.

kind regards,

Jos

[viren2727in]

ImageStack stack = null;
for (int i=0; i<files.length; i++) {
    ImagePlus img = opener.openImage(path, files[i].getName());
    if (i==0) {
        stack = new ImageStack(img.getWidth(), img.getHeight(), 2);
    }
 
    if (img!=null) {
        img.show();
        stack.addSlice(files[i].getName(),img.getProcessor().getPixels());
        }
}
....
stack = null; // In Last

[JosAH]

Setting a (non existent) variable to null doesn't help one bit.

kind regards,

Jos

[Snackers]

The variable 'stack' is local to that first if-statement body; define it before line #3 and it still exists in the second if-statement.

kind regards,

Jos

Thanks that worked!