title: _OBJC_IVAR_$_Answer.answer"
body: <p>I have a class that holds number ivars:</p>
  
  <pre><code>//  Answer.h
  
  #import &lt;Foundation/Foundation.h&gt;
  
  
  @interface Answer : NSObject{
      @public
      int firstNumber;
      int secondNumber;
      char myOperator;
  }
  
  @end
  </code></pre>
  
  <p>I try to access the code here</p>
  
  <pre><code>    numberGroup-&gt;firstNumber = arc4random() % 1;
      numberGroup-&gt;secondNumber = arc4random() % 10;
      numberGroup-&gt;myOperator = arc4random() % 4;
  </code></pre>
  
  <p>and I get this error:</p>
  
  <blockquote>
    <p>Ld
    /Users/jack/Library/Developer/Xcode/DerivedData/PowerBuilders-emehzkfcgntrhofxhvurovjmnugn/Build/Products/Debug-iphonesimulator/PowerBuilders.app/PowerBuilders
    normal i386
        cd "/Users/jack/Desktop/Xcode/Assorted Apps/PowerBuilders"
        setenv MACOSX_DEPLOYMENT_TARGET 10.6
        setenv PATH "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:/usr/bin:/bin:/usr/sbin:/sbin"
        /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang
    -arch i386 -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator5.1.sdk
    -L/Users/jack/Library/Developer/Xcode/DerivedData/PowerBuilders-emehzkfcgntrhofxhvurovjmnugn/Build/Products/Debug-iphonesimulator
    -F/Users/jack/Library/Developer/Xcode/DerivedData/PowerBuilders-emehzkfcgntrhofxhvurovjmnugn/Build/Products/Debug-iphonesimulator
    -filelist /Users/jack/Library/Developer/Xcode/DerivedData/PowerBuilders-emehzkfcgntrhofxhvurovjmnugn/Build/Intermediates/PowerBuilders.build/Debug-iphonesimulator/PowerBuilders.build/Objects-normal/i386/PowerBuilders.LinkFileList
    -mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -fobjc-arc -Xlinker -no_implicit_dylibs -D__IPHONE_OS_VERSION_MIN_REQUIRED=50100 -framework UIKit -framework Foundation -framework CoreGraphics -o
    /Users/jack/Library/Developer/Xcode/DerivedData/PowerBuilders-emehzkfcgntrhofxhvurovjmnugn/Build/Products/Debug-iphonesimulator/PowerBuilders.app/PowerBuilders</p>
    
    <p>Undefined symbols for architecture i386:<br>
    "_OBJC_IVAR_$_Answer.firstNumber", referenced from:
          -[ViewController lesson1] in ViewController.o   "_OBJC_IVAR_$_Answer.myOperator", referenced from:
          -[ViewController lesson1] in ViewController.o   "_OBJC_IVAR_$_Answer.secondNumber", referenced from:
          -[ViewController lesson1] in ViewController.o ld: symbol(s) not found for architecture i386 clang: error: linker command failed with
    exit code 1 (use -v to see invocation)</p>
  </blockquote>