What does the FIND function return if the substring is not found in the string?

The FIND function in SAS is used to locate the position of a specified substring within a string. If the substring is not found, the function returns a value of zero. This indicates the absence of the substring within the specified string, which allows the programmer to easily identify that the search was unsuccessful.

When the FIND function operates successfully, it returns the starting position of the substring. If the substring appears at the first character, the return value would be 1. However, if the substring does not occur in the target string at all, a return value of zero clearly communicates this, making it a straightforward way to handle such cases in programming logic. This behavior is critical for ensuring accurate string manipulations and conditional checks within SAS programming.