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	WHAT'S YOUR ENGINEERING QUOTIENT?
Problem 1—What is the difference between the declaration and the definition of a symbol? Answer: The declaration of a symbol tells the compiler what kind of symbol it is. This allows the compiler to generate code that correctly accesses the symbol. The definition of a symbol actually allocates space for and defines the contents of the symbol. The difference is important when you are building a project from separately-compiled modules that need to share data and subroutines. Each shared item should be declared wherever it is used, but defined only once. For example, in C, you might put the declaration extern int debug_flag; in an include file used by all modules that need to access `debug_flag`. However, only one source file will contain the definition: int debug_flag = 0; Contributor: Naveen P N 8-01 — NEXT Q&A For questions or comments about Test Your EQ, e-mail eq@circuitcellar.com.