In android JUnit test, we may need to know if the target app is debug version or release version.

Context mContext = InstrumentationRegistry.getTargetContext();
ApplicationInfo mApplicationInfo = mContext.getPackageManager().getPackageInfo(PACKAGE_NAME, 0).applicationInfo;
boolean isDebuggable = (0 != (mApplicationInfo.flags & ApplicationInfo.FLAG_DEBUGGABLE));

And we can check other flags using this, FLAG_ALLOW_CLEAR_USER_DATA etc.

As for & in inta & intb:

int a = Integer.parseInt("1010", 2);
int b = Integer.parseInt("0111", 2);
System.out.println(a & b);
System.out.println(Integer.toBinaryString(a & b));

prints:

2
10