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To avoid critical completion of programs, the previous version compiler handled many errors in the runtime environment. For example, division by zero or array out of range are critical errors and usually lead to program crash. The new compiler can detect actual or potential sources of errors and improve code quality. In this article, we discuss possible errors that can be detected during compilation of old programs and see how to fix them.

In this article, we discuss possible errors that can be detected during compilation of old programs and ways to fix them.

1. Compilation Errors
   
   
   • 1.1. Identifier coincides with a reserved word
   • 1.2. Special characters in the names of variables and functions
   • 1.3. Errors using the switch operator
   • 1.4. Function return values
   • 1.5. Arrays in function arguments
   
   
2. Runtime Errors
   
   
   • 2.1. Array out of range
   • 2.2. Zero divide
   • 2.3. Use of 0 instead of NULL for the current character
   • 2.4. Unicode format strings and their use in a DLL
   • 2.5. File sharing
   • 2.6. Datetime conversion
   
   
3. Compiler Warnings
   
   • 3.1. Names of global and local variables coincide
   • 3.2. Mismatch of types
   • 3.3. Unused variables

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