What is a macro, and how do you use it?

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Chetan Santha

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A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro. There are two kinds of macros. They differ mostly in what they look like when they are used. Object-like macros resemble data objects when used, function-like macros resemble...
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A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro. There are two kinds of macros. They differ mostly in what they look like when they are used. Object-like macros resemble data objects when used, function-like macros resemble function calls. read less
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A macro is a name given to a block of C statements as a pre-processor directive. Being a pre-processor, the block of code is communicated to the compiler before entering into the actual coding (main () function). A macro is defined with the preprocessor directive, #define. Before compilation, the name...
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A macro is a name given to a block of C statements as a pre-processor directive. Being a pre-processor, the block of code is communicated to the compiler before entering into the actual coding (main () function). A macro is defined with the preprocessor directive, #define. Before compilation, the name of macro is replaced by the defined macro body. The speed of the execution of the program is the major advantage of using a macro. Disadvantage: The size of the program is large. Example: #include"stdio.h" #define X 100 void main() { printf("%d",X); } read less
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Oracle, Hindi, C++, C, MS Office, VBScript,JavaScript,Spoken English etc with 32 years of experience

Macros automate frequently-used tasks; many are created with VBA and are written by software developers. However, some macros pose a potential security risk.
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printf ("File Name = %s.\n",__FILE__);
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macro is single line code block, e.g. #define area(r) (3.1415*(r)*(r)) where ever you refer to the macro area(r), it will be replace with the actual code block defined in macro radius=10; area=area(radius); so in the above code the macro is replaced with the actual code area=(3.1415*(radi...
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macro is single line code block, e.g. #define area(r) (3.1415*(r)*(r)) where ever you refer to the macro area(r), it will be replace with the actual code block defined in macro radius=10; area=area(radius); so in the above code the macro is replaced with the actual code area=(3.1415*(radius)*(radius)) read less
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Gcc website says "A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro." In our terms, A macro is something prefixed by a # and used be preprocessor. There are various macros like define,ifdef,ifndef,if,include etc. Its very...
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Gcc website says "A macro is a fragment of code which has been given a name. Whenever the name is used, it is replaced by the contents of the macro." In our terms, A macro is something prefixed by a # and used be preprocessor. There are various macros like define,ifdef,ifndef,if,include etc. Its very easy to use but you must understand when to use one. read less
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Macro is a very useful construct. Basically it is a piece of code with name. Macros are declared using #Define preprocessor directive. these are used to define constants as well as functions. e.g. pi is a constant hence instead of declaring it as a variable like float pi=3.14 it can be declared as...
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Macro is a very useful construct. Basically it is a piece of code with name. Macros are declared using #Define preprocessor directive. these are used to define constants as well as functions. e.g. pi is a constant hence instead of declaring it as a variable like float pi=3.14 it can be declared as a constant like #Define pi 3.14. e.g. #Define area(l,b) (2(l+b)) whenever pi or area(l,b) will be used they will expand to 3.14 and (2(l+b)). user has to pass the appropriate value for l(length) and b(breadth) i.e. whenever the compiler find a macro name it replaces the name with its contents. A macro is accessible to all the functions of the program. e.g. if pi is defined as a variable then it will be accessible by the function where it is declared but if declared using #Define then it is accessible by all the functions of the program. read less
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Macro is a preprocessor directive we can give any name to any thing it doesn't give any errors compailer replace that names preprocessor stage only
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International Corporate Trainer For dotnet Core ,Angular 2 ,C ,C++ and LPT Marathi for RBI Banking

Macro in C is also called symbolic constant , it replaces the code part. ex:#define line "\n..................\n", ex: #define Square(x) (x)*(x), this is called function macro it will work as Square(5) = 25 but it is not type safe user may enter alphabet instead of number and progam will fail. better...
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Macro in C is also called symbolic constant , it replaces the code part. ex:#define line "\n..................\n", ex: #define Square(x) (x)*(x), this is called function macro it will work as Square(5) = 25 but it is not type safe user may enter alphabet instead of number and progam will fail. better way is to use user defined function read less
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In simplest form think of Macro as search and replace by pre-processor: example: #define MAX(a,b) a>b?a:b void f() { int i=5; int j=3; int m = MAX(i,j); }
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