Creating and Using Ranges

Many Core Foundation take ranges—a structure of type CFRange—as parameters. A range is a measure of a linear segment; it has a beginning location and a length. To create and initialize this structure you can use the convenience function CFRangeMake.

The following code fragment gets the number of subsequent elements in an array that match the first element:

CFRange aRange = CFRangeMake(1, CFArrayGetCount(array) - 1);

// Since start is 1, length of remainder of range is count-1

const void *aValue = CFArrayGetValueAtIndex(array, 0);

CFIndex numVals = CFArrayGetCountOfValue(array, aRange, aValue);