title: How to check the NSString contains the '%' or not?
body: <p>I want to ask a question about the objective C. Does the NSString * contains some functions to check the NSString * contains some string in the UITextField.text? For example</p>
  
  <pre><code>NSString *checkString = @"abcd%"
  
  if(checkString contains '%') // I want this function
     return YES;
  else
     return NO;
  </code></pre>