title: Change NSNumberFormatter's negative format from (xxx.xx) to -xxx.xx
body: <p>I want to change my NSNumberformatter from displaying negative numbers with parenthesis around them to putting the minus sign in front (or whatever the localized standard is). </p>
  
  <p>I would assume I could do this with setNegativeFormat: </p>
  
  <p>but reading Apple's oh so thorough docs I am left scratching my head:</p>
  
  <hr>
  
  <p><strong>setNegativeFormat:</strong></p>
  
  <p>Sets the format the receiver uses to display negative values.</p>
  
  <pre><code>- (void)setNegativeFormat:(NSString *)aFormat
  </code></pre>
  
  <p><strong>Parameters</strong>
  aFormat
  A string that specifies the format for negative values.</p>
  
  <p><strong>Availability</strong>
  Available in iPhone OS 2.0 and later.</p>
  
  <p><strong>See Also</strong>
  – negativeFormat</p>
  
  <p><strong>Declared In</strong>
  NSNumberFormatter.h</p>
  
  <hr>
  
  <p>what are my options for aFormat?!?  C'mon Doc Writers, would a link here kill you?</p>
  
  <p>edit: for what it's worth here's the declaration:</p>
  
  <pre><code>NSNumberFormatter *currencyFormatter = [[NSNumberFormatter alloc] init];
  [currencyFormatter setNumberStyle:NSNumberFormatterCurrencyStyle];
  </code></pre>
  
  <p>It's important for me to retain the localized currency symbol &amp; decimal places whatever they may be. So [currencyFormatter setNegativeFormat:@"-#,##0.00"] probably won't work as currency is missing and 2 decimals can't be assumed for all currencies. </p>