C language is a widely used computer programming language that is efficient, flexible and powerful. To be proficient in programming in C language, you first need to understand its basic syntax and data types. This article will introduce the basic syntax and data types of C language and give examples.
1. Basic syntax
1.1 Comments
In C language, comments can be used to explain the code to facilitate understanding and maintenance. Comments can be divided into single-line comments and multi-line comments.
// This is a single line comment /* This is Multi-line comments */
1.2 Keywords
There are some keywords in C language that are used to express specific meanings and cannot be used as variable names. Common keywords include int
, char
, if
, else
, etc.
1.3 Variable declaration
In C language, variables need to be declared first and then used. When declaring a variable, you need to specify the variable type and variable name.
int num; // Declare an integer variable num
1.4 Function definition
In C language, a function is the execution unit of code, used to encapsulate specific functions . Function definition includes function return type, function name, parameter list and function body.
int add(int a, int b) { return a b; }
1.5 Conditional statements
Conditional statements are used to execute different code blocks based on conditions. Common conditional statements include if
statements and if-else
statements.
int x = 5; if (x > 0) { printf("x is positive"); } else { printf("x is non-positive"); }
1.6 Loop statement
Loop statement is used to repeatedly execute a specific block of code. Common loop statements include for
loop, while
loop and do-while
loop.
for (int i = 0; i < 5; i ) { printf("%d ", i); }
2. Data types
2.1 Basic data types
C language provides some basic data types for storing different types of data. Common basic data types include int
, char
, float
, and double
, etc.
int num = 10; char ch = 'A'; float f = 3.14; double d = 3.1415926;
2.2 Array
An array is a collection that stores data of the same type. Array elements are accessed through subscripts. The declaration of an array requires specifying the array type and array size.
int arr[5] = {1, 2, 3, 4, 5};
2.3 Pointer
Pointer is a variable that stores the address of a variable and is used for indirect access data in memory. Pointer variables need to specify the pointer type and the variable type pointed to.
int *ptr; int num = 10; ptr = #
2.4 Structure
Structure is a custom data type that can store multiple different types of data. The declaration of a structure requires specifying the structure name and member variables.
struct Student { char name[20]; int age; }; struct Student stu;
Through the above introduction, we understand the basic syntax and data types of C language. To master the C language proficiently, you need to practice more and continue to study in depth. Hope this article helps you!
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