The basic knowledge of C language must be memorized

The basics of C language cover data types (integrals, floating point numbers, characters, booleans), variable declarations, operators, process controls, functions, arrays, strings, pointers, and structures. These concepts provide the basis for C language programming, including: integer type: int, short, long floating point type: float, double variable declaration: data_type variable_name; if statement: conditional judgment and code execution for loop: repeat code function definition by specific times: return_type function_name(parameter_list); array declaration: data_type array_name[si

C language basic knowledge must be memorized

1. Data type

• Integer types: int, short, long
• Float number type: float, double
• Character type: char
• Boolean type: bool

2. Variables

• Declare variable: data_type variable_name;
• Variable name rules: start with a letter or an underscore, followed by letter, number or underscore

3. Operators

• Arithmetic operators: -, *, /, %
• Relational operators: ==, !=, , =
• Logical operators: &&, ||, !

4. Process control

• if statement: determine whether the condition is true and execute the corresponding code block
• switch statement: select different code blocks according to the variable value to execute
• for loop: Repeat code blocks for a specific number of times
• while loop: Repeat the code block until the condition is false

V. Function

• Define function: return_type function_name(parameter_list);
• Call function: function_name(argument_list);

6. Array

• Declare array: data_type array_name[size];
• Access array elements: array_name[index]

7. Character string

• Declare string: char string_name[];
• Commonly used functions of strings: strcpy(), strcat(), strlen()

8. Pointer

• Definition pointer: data_type *pointer_name;
• Access the value pointed to by the pointer: *pointer_name
• Pointer operation: ,-, , --

9. Structure

• Define structure: struct structure_name { data_type member_name; };
• Access structure member: structure_name.member_name

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