<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div><blockquote type="cite" class=""><div class="">On May 18, 2016, at 7:35 PM, Nathan Day <<a href="mailto:nathan_day@mac.com" class="">nathan_day@mac.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><span style="font-family: Alegreya-Regular; font-size: 15px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">In objective-c I have come across something like this a lot where a NSDictionary has been created from JSON an a NSNull is used to represent an actual null in the source JSON versus the absence of the key</span></div></blockquote></div><br class=""><div class="">Yeah, this comes from JavaScript, which weirdly has both ‘null’ and ‘undefined’ values; they’re kind of similar but not the same, and the latter is more like what we think of as null/nil in Swift or Obj-C. I think this was a bad design, and unfortunately it crept into JSON, which was based on JavaScript literals.</div><div class=""><br class=""></div><div class="">—Jens</div></body></html>