One of the biggest advantages of web services is their interoperability. They can be called from programs using a variety of programming languages, in other words. Consider, for example, the following web service that provides two methods, Uppercase and Lowercase, that return the uppercase or lowercase equivalents of the character strings they receive:
This particular web service was written using the C# programming language within a .Net environment. The following C# program uses the methods the web service provides:
When you compile and execute this program, it will display the following output:
Because they are interoperable, web services can be called from different programming languages. The following PHP script uses the web service:
When you run this script, it will display the following output: