Where does the execution of a C language start?

The execution of a C language starts from the main function. The execution process of C language is as follows: 1. Program loading, the operating system will load the executable file into the memory; 2. Main function, the entry point of the C program, all C programs must contain a main function; 3. Variable declaration and initialization, the memory location used to store data; 4. Execution statements, statements are the basic execution unit of C language; 5. Function calls, used to perform specific tasks; 6. Control flow, using conditional judgment statements and loop statements to Control the execution process; 7. Return value, etc.

#The operating environment of this article: Windows 10 system, Dell G3 computer.

The execution of C language starts from the entry point of the program. In C language, the entry point of the program is the main function. When a program is executed, the operating system finds and loads the executable file, and then starts execution from the main function.

Specifically, the execution process of C language is as follows:

Program loading: The operating system will load the executable file into the memory and allocate necessary resource.

main function: The program will start executing from the main function. The main function is the entry point of a C program. It is a special function. All C programs must contain a main function.

Variable declaration and initialization: In the main function, variables can be declared and initialized. Variables are memory locations used to store data that can be used within a program.

Execution statements: In the main function, you can write a series of statements to achieve the required functions. Statement is the basic execution unit of C language, which can include operations such as assignment, conditional judgment, and looping.

Function call: In the main function, other functions can be called to perform specific tasks. A function is a block of code that encapsulates a series of operations and can be used repeatedly.

Control flow: During the execution process, you can use conditional judgment statements (such as if statements) and loop statements (such as for loops) to control the execution flow of the program. Depending on the conditions, the program can choose different execution paths.

Return value: When the main function is executed, a value can be returned to the operating system through the return statement. This return value can be used to indicate the execution status of the program. It is generally agreed that returning 0 indicates that the program ends normally, and a non-zero value indicates that the program ends abnormally.

Summary

The execution of C language starts from the main function, and then executes the code in the program line by line in the order of statements. During the execution process, you can declare variables, execute statements, call functions, and control the execution path of the program through control flow statements. Finally, a value is returned to the operating system through the return statement, indicating the execution status of the program.

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