title: Remove an object with conditions in NSArray
body: <p>For example, i have an array like that, in each object there are types of objects:</p>
  
  <pre><code>{
     {//ob1
     name = "zmg";
     link = "abccom";
     adress = "123 street";
     son = "2";
     },
  
     {//ob2
     name = "asf";
     link = "http://fsdfabccom";
     adress = "123 street";
     son = "1";
     },
  
     {//ob3
     name = "asf";
     adress = "123 street";
     son = "5";
     },
  
     {//ob4
     name = "sadfsdfasdf";
     link = "http://fsdfasdfasdfabc.com";
     adress = "123 street";
     son = "2";
     },
  
     {//ob5
     name = "asf";
     adress = "123 street";
     son = "4";
     },
  }
  </code></pre>
  
  <p>What can I do if i want to delete all object, in which there is no object "link" (in this example: ob3, ob5 must be removed);
  The result must be:</p>
  
  <pre><code>{
     {//ob1
     name = "zmg";
     link = "abccom";
     adress = "123 street";
     son = "2";
     },
  
     {//ob2
     name = "asf";
     link = "http://fsdfabccom";
     adress = "123 street";
     son = "1";
     },
     {//ob3
     name = "sadfsdfasdf";
     link = "http://fsdfasdfasdfabc.com";
     adress = "123 street";
     son = "2";
     },
  
  }
  </code></pre>
  
  <p>Thank u so much!</p>