title: unrecognized selector sent to class when create a singleton object
body: <p>I have a shared class</p>
  
  <p><code>.h</code></p>
  
  <p>`</p>
  
  <pre><code>#import &lt;Foundation/Foundation.h&gt;
  
  @interface ArraysClass : NSObject
  
  @property(nonatomic,copy)NSMutableArray *mutArraySongs;
  
  
  +(ArraysClass *)SharedManager;
  
  @end
  </code></pre>
  
  <p>`</p>
  
  <p><code>.m</code></p>
  
  <p>`</p>
  
  <pre><code>#import "ArraysClass.h"
  
  @implementation ArraysClass
  
  static ArraysClass *sharedService = nil;
  
  #pragma mark -
  #pragma mark Singleton Methods
  
  +(ArraysClass *)sharedManager {
      if(sharedService == nil){
      sharedService = [[super allocWithZone:NULL] init];
  }
  return sharedService;
  }
  
  
  - (id)copyWithZone:(NSZone *)zone {
  return self;
   }
  
  -(id)init {
  self = [super init];
  if (self != nil) {
      // initialize stuff here
     // user=[LoggedUser sharedManager];
  }
  
  return self;
  </code></pre>
  
  <p>}</p>
  
  <p>@end</p>
  
  <p>`</p>
  
  <p>In my <code>ViewController</code> I need to create an object from this. I did like this</p>
  
  <p>`</p>
  
  <pre><code> #import "ArraysClass.h"
   ArraysClass *arrayClass=[ArraysClass SharedManager];
  </code></pre>
  
  <p>`</p>
  
  <p>But this last line giving me an exception like this</p>
  
  <p><code>*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '+[ArraysClass SharedManager]: unrecognized selector sent to class 0x13e9c8'
  </code></p>
  
  <p>why is that? and how can I solve this problem? Please help me</p>