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Cprogramming~5 mins

main function and program entry - Cheat Sheet & Quick Revision

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beginner
What is the purpose of the main function in a C program?
The main function is the starting point of a C program. When you run the program, the computer begins executing instructions from main.
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beginner
What does the signature int main(void) mean?
int main(void) means the main function takes no arguments and returns an integer value to the operating system, usually 0 to indicate success.
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beginner
Why do we return 0 at the end of the main function?
Returning 0 tells the operating system that the program finished successfully. Other values can indicate errors.
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beginner
Can a C program have more than one main function?
No, a C program must have exactly one main function. It is the unique entry point for the program.
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beginner
What happens if you omit the main function in a C program?
The program will not compile or link because the system does not know where to start executing instructions.
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What is the role of the main function in a C program?
AIt stores global variables.
BIt is the starting point where program execution begins.
CIt compiles the program.
DIt handles input/output operations only.
What does the return value of main usually indicate?
AWhether the program ended successfully or with an error.
BThe size of the program in bytes.
CThe number of lines in the program.
DThe number of functions called.
Which of these is a valid signature for the main function?
Achar main()
Bvoid main()
Cfloat main(int)
Dint main(void)
What happens if a C program has no main function?
AIt fails to compile or link.
BIt compiles but crashes at runtime.
CIt runs but skips main.
DIt runs normally.
Can a C program have multiple main functions?
AYes, but only if they have different names.
BYes, to handle different tasks.
CNo, only one <code>main</code> function is allowed.
DYes, if they are in different files.
Explain the role of the main function in a C program and why it is important.
Think about where the computer starts running your code.
You got /4 concepts.
    Describe what happens if you forget to include a main function in your C program.
    Consider how the system knows where to start.
    You got /3 concepts.