Databases
StackOverflow2013
Postsdbo
POWhat would cause objectForKey: to return null with a valid string in place?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhat would cause objectForKey: to return null with a valid string in place?
    primarykey
    data
    text
    <p>I am having an issue with <code>NSDictionary</code> returning <code>null</code> for an <code>NSString</code> even though the string is in the dictionary. Here is the code:</p> <pre><code>- (void)sourceDidChange:(NSNotification *)aNote { NSDictionary *aDict = [aNote userInfo]; DLog(@"%@", aDict); NSString *newSourceString = [aDict objectForKey:@"newSource"]; DLog(@"%@", newSourceString); newSourceString = [newSourceString stringByReplacingOccurrencesOfString:@" " withString:@""]; DLog(@"%@", newSourceString); NSString *inspectorString = [newSourceString stringByAppendingString:@"InspectorController"]; DLog(@"%@", inspectorString); newSourceString = [newSourceString stringByAppendingString:@"ViewController"]; DLog(@"%@", newSourceString); } </code></pre> <p>And I get the following log statements:</p> <pre><code>2010-04-17 23:50:13.913 CoreDataUISandbox[13417:a0f] -[RightViewController sourceDidChange:] { newSource = "Second View"; } 2010-04-17 23:50:13.914 CoreDataUISandbox[13417:a0f] -[RightViewController sourceDidChange:] (null) 2010-04-17 23:50:13.916 CoreDataUISandbox[13417:a0f] -[RightViewController sourceDidChange:] (null) 2010-04-17 23:50:13.917 CoreDataUISandbox[13417:a0f] -[RightViewController sourceDidChange:] (null) 2010-04-17 23:50:13.917 CoreDataUISandbox[13417:a0f] -[RightViewController sourceDidChange:] (null) </code></pre> <p>As you can see, the string is in the dictionary under the key <code>newSource</code>, yet when I call <code>objectForKey:</code>, I get <code>null</code>. I have even tried the fallback option of cleaning the project.</p> <p>Has anyone ever run into this, or have I just forgotten something really basic?</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USSteve Harrison
    1. UStheMikeSwan
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. This table or related slice is empty.
      1. VTUpMod
    1. COOut of curiosity, after setting and logging `aDict`, what happens if you do `DLog(@"%@", [aDict allKeys]);`?
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. USIsaac
    2. COIs this the *actual* code? Any chance you mis-typed the key? What does `DLog(@"%@", [aDict allKeys])` give?
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. USBarry Wark
    3. COYou might also want to try logging `newSourceString` with `%p` instead of `%@`.
      singulars
      1. POWhat would cause objectForKey: to return null with a valid string in place?
      1. USPeter Hosey
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload