Verifies that the specified string is contained in the mapping source string or that the string begins with the specified string, and assigns the logical value to the mapping destination.
To verify that the specified string is contained in the mapping source string or that the string begins with the specified string, and assign the logical value to the mapping destination, you use the check string function. The following figure shows an example that uses the check string function.
Figure 6-5 Usage example of the check string function
To check the string of the mapping source and assign the logical value to the mapping destination: