Changes

@end

</pre>

The first step is to instruct Objective-C to synthesize accessor methods for our tempText and resultLabel objects and then to implement the convertTemp method. The relevant section of the ''UnitConverterViewController.m'' file should now read as follows:

With this in mind, select the ''UnitViewController.xib'' file to load the user interface into Interface Builder. We will begin by connecting the IBOutlet instance variables we created in our view controller class to the label and text field objects respectively. Located in the narrow panel to the left of the graphical view of the user interface are three icons. Clicking on the small square with the black triangle at the bottom of this panel will expand the panel to provide more detail:

[[Image:xcode_4_placeholders.jpg|The File's Owner and other objects in Xcode 4]]

<hr>

<table border="0" cellspacing="0" width="100%">