Linker command failed when declaring int variable

Question

When i declare a global variable, I get the error:

linker command failed with exit code 1 (use -v to see invocation)

Here is the code:

import "menuplay.h"

import "buttonmanager.h"

int  test; //<--------------when i  declare  it show  error Apple Mach-O Linker Error

@interface lessonone : CCLayer {
...
}

Answer 1

Declare it static:

static int test;

Or const if its value should never change:

const int test = 10;