What is the execution order of C language?

C language execution sequence is: 1. Preprocessing instructions, the C compiler will process the preprocessing instructions first; 2. Function definition, the code in the function body will be executed when the function is called; 3. main function , the main function is the entry point of the program; 4. Variable declaration and initialization, used to tell the compiler to allocate a certain amount of memory space in the program; 5. Expressions and statements, use various expressions and statements to perform specific operations; 6 , Function calls, calling other functions to perform specific tasks; 7. Control flow statements, executing different code blocks based on conditions or loops; 8. Ending the program.

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

The execution order of C language is to execute the code line by line from top to bottom. During the execution of the program, it will execute different statements and expressions in the following order:

1. Preprocessing instructions: Before compiling the code, the C compiler will first process the preprocessing instructions. These instructions usually start with "#" and are used to include header files, macro definitions, conditional compilation, etc.

2. Function definition: The function definition in the program is usually located before the main function. A function definition includes the function's declaration and function body, where the code in the function body will be executed when the function is called.

3. Main function: The execution of the C program starts from the main function. The main function is the entry point of the program and contains the main logic of the program.

4. Variable declaration and initialization: In the main function, variables can be declared and initialized. The declaration of a variable is used to tell the compiler to allocate a certain amount of memory space in the program, while initialization assigns an initial value to the variable.

5. Expressions and statements: In the main function, you can use various expressions and statements to perform specific operations. Expressions can be mathematical operations, logical operations, bit operations, etc., while statements can be assignment statements, conditional statements, loop statements, etc.

6. Function call: In the main function, other functions can be called to perform specific tasks. Function calls can pass parameters, pass parameters to the called function, and receive results returned by the function.

7. Control flow statements: C language provides a variety of control flow statements for executing different code blocks based on conditions or loops. These statements include conditional statements (if-else, switch), loop statements (for, while, do-while), and jump statements (break, continue, return).

8. End the program: When the program finishes executing the code in the main function or encounters a return statement, the program will end execution and return to the operating system.

It should be noted that C language is a programming language with a sequential structure, and it is executed line by line in the order in which the code is written. However, during program execution, you can also use function calls, control flow statements, loop statements, etc. to change the order of execution.

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