CFStringGetRange

CFStringGetRange is a function within the Core Foundation framework in macOS and iOS. It is used to retrieve a range from a CFString object. The function takes two arguments: a CFString object and an integer representing the desired range. The integer can be zero or a positive value. If the integer is zero, the function returns the entire range of the string. If the integer is a positive value, it returns a range starting from that index to the end of the string.

The CFStringGetRange function returns a CFRange structure, which is a data type that represents a range of characters within a string. A CFRange structure contains two members: the location of the start of the range and the length of the range. The location is a zero-based index, and the length is the number of characters in the range.

This function is useful for various string manipulation tasks, such as extracting substrings, performing character searches, or validating string content. For example, one might use CFStringGetRange to get the range of the last word in a sentence or to check if a specific character exists within a certain portion of a string. It is a fundamental tool for working with strings in Objective-C and Swift when utilizing the Core Foundation framework.