Basics of C language programming: starting from the basic units

As a widely used programming language, C language is the first choice for many programmers to get started. As an intermediate programming language, it has good portability, efficiency and feature richness, so it is very popular among programmers. This article will start with the basic units of C language to introduce its programming foundation, including data types, variables, constants, operators, etc., along with specific code examples to help readers better understand and master the basic knowledge of C language.

1. Data type

In C language, data type is used to define the storage format of data and the operations that can be performed on the data. C language provides some basic data types, such as integer, floating point, character, etc.

Integer type (int)

Integer type is used to represent integers. In C language, use the keyword int to declare integer variables. The following is an example code for the definition and assignment of an integer variable:

int num1; // Declare an integer variable
num1 = 10; //Assign a value to a variable

Float type (float)

Floating point type is used to represent a value with a decimal part. Use the keyword in C language float to declare floating point variables. The following is a sample code for the definition and assignment of a floating-point variable:

float num2; // Declare a floating-point variable
num2 = 3.14; // Assign a value to the variable 

Character type (char)

Character type is used to represent a single character, and is declared using the keyword char in C language Character variable. The following is a sample code for the definition and assignment of a character variable:

char ch; // Declare a character variable
ch = 'A'; // Assign values ??to variables 

2. Variables

Variables are used to store data that need to be processed when the program is running. In C language, they need to be declared first and then used. The following is a sample code for variable declaration and use:

int a, b, sum; // Declare integer variables a, b, sum
a = 10; // Assign a value to variable a
b = 20; // Assign a value to variable b
sum = a b; // Assign the sum of a and b to the variable sum

3. Constant

A constant is a fixed value, using the keyword ## in C language #const to declare constants. The following is a sample code for the declaration and use of a constant:

const float PI = 3.14; // Declare a constant PI and assign the value to 3.14 float radius = 5; // Declare a variable radius and assign it a value of 5 float area = PI * radius * radius; // Calculate the area of ??a circle

4. Operator

The C language provides a wealth of operators for operating on data, including arithmetic operations operators, assignment operators, logical operators, etc. The following are some commonly used operator sample codes:

Example of arithmetic operators:

int a = 10, b = 20;
int sum, difference, product, quotient, remainder;

sum = a b; // addition operation
difference = a - b; // subtraction operation
product = a * b; // multiplication operation
quotient = a / b; // division operation
remainder = a % b; // Remainder operation

Assignment operator example:

int num = 10;
num = 5; // num = num 5;
num -= 3; // num = num - 3;
num *= 2; // num = num * 2;
num /= 4; // num = num / 4;

Logical operator example:

int x = 10, y = 20;
int result;

result = (x > y) && (x != 0); // Logical AND operation, if x is greater than y and x is not equal to 0, the result is 1, otherwise it is 0
result = (x < y) || (x == 10); // Logical OR operation, if x is less than y or x is equal to 10, the result is 1, otherwise it is 0

Through the above introduction and Code examples hope that readers can have a clearer understanding of the basic units of C language, and then be able to learn and apply C language programming more deeply. During the learning process, continuous practice and writing code are the keys to improving programming abilities. I hope readers can persevere and master the basic knowledge of C language, so that they can write more efficient and reliable programs. I wish readers success in learning C language!

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