Comprehensive collection of C language function libraries: an essential reference book to improve programming efficiency

Introduction:
In the world of programming, function libraries are the most important thing for programmers. One of the important tools. Function libraries can reduce code duplication and improve programming efficiency. They can also broaden programmers' thinking and stimulate creativity. As a widely used programming language, C language has a rich function library. This article will introduce some important C language function libraries to readers and provide specific code examples.

1. stdio.h (standard input and output library)
stdio.h library is one of the most commonly used function libraries in C language. It provides many functions for standard input and output. The following is sample code for some commonly used functions:

1. printf function (output function)

include

int main()
{

char name[] = "John";
int age = 20;
printf("My name is %s and I am %d years old.

", name, age);

return 0;

}

2. scanf function (input function)

include< ;stdio.h>

int main()
{

char name[20];
printf("Please enter your name: ");
scanf("%s", name);
printf("Hello, %s!

", name);

return 0;

}

2. stdlib.h (Standard library)
stdlib.h is the standard library in C language. It provides some common functions, mainly including memory management, string conversion and other functions.

1. malloc function (dynamic memory allocation)

include

include

int main()
{

int *ptr;
ptr = (int*)malloc(5 * sizeof(int));
if(ptr == NULL)
{
    printf("Memory allocation failed.

");

    exit(1);
}
for(int i = 0; i < 5; i++)
{
    ptr[i] = i;
}
for(int i = 0; i < 5; i++)
{
    printf("%d ", ptr[i]);
}
free(ptr);
return 0;

}

2. atoi function (string to integer)

include

include

int main()
{

char str[] = "12345";
int num = atoi(str);
printf("The converted integer is: %d

", num);

return 0;

}

3. math.h (mathematical function library)
math.h library provides many mathematical functions for numerical calculations, trigonometric functions, exponential operations, etc.

1. sqrt function (square root function)

include

include

int main ()
{

double num = 16;
double result = sqrt(num);
printf("The square root of %f is: %.2f

", num, result);

return 0;

}

2. pow function (power function)

include

include

int main()
{

double base = 2;
double exponent = 3;
double result = pow(base, exponent);
printf("The result of %.2f raised to the power of %.2f is: %.2f

", base, exponent, result);

return 0;

}

Summary:
This article introduces some commonly used function libraries in C language and their specific code examples. These function libraries can greatly improve programming efficiency by providing rich functions and methods. Of course, the use of function libraries requires choosing the appropriate function library according to different projects and needs. I hope this article can help readers better understand the role of function libraries and improve their programming skills.

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