C 语言常用的基本数据类型

1.常量和变量

#include <stdio.h>

#define MY_AGE 10000

const int MY_AGE1 = 10000;//推荐方法

int main() {
    int a = 10;
    printf("The num is %d \n",a);
    a = 11;
    printf("The num is %d \n",a);

    printf("My age is : %d\n",MY_AGE);
    printf("My age is : %d\n",MY_AGE1);
    return 0;
}

2.整型数据

#include <iostream>


int main() {
    int a = 10;
    int b = -10;
    long long c = 20;
    printf("a=%d,b=%d,c=%lli\n", a, b, c);

    int d = 0b100;//二进制
    int e = 0xB;//十六进制
    int f = 010;//八进制
    printf("d=%d,e=%d,f=%d\n", d, e, f);

    unsigned int g = 12;
    printf("g=%d\n", g);

    //_t结尾  所有平台一样
    int32_t h = 10;
    int8_t i = 127;//-128-----127
    uint8_t j = 200;//0------255
    printf("h=%d,i=%d,j=%d\n", h, i, j);
    return 0;
}

3.实型数据

#include <iostream>

int main() {
    float a = 3.1;//单精度,4字节，32位
    double b = 3.1;//双精度，8字节，64位
    long double c = 3.1;//长双精度，16字节，128位
    printf("a=%f,b=%f,c=%Lf\n", a, b, c);
    return 0;
}

4.字符型数据

#include <iostream>


int main() {

    printf("Hello\nWorld\n");//换行
    printf("Hello\rWorld\n");//回车
    printf("Hello\bWorld\n");//退格
    printf("Hello\tWorld\n");//制表
    printf("Hello\fWorld\n");//换页

    printf("\\,\"\n");

    printf("length of char : %d\n", (int) sizeof(char));

    char ch1 = 'a';
    char ch2 = 'A';
    printf("%d,%d\n", ch1, ch2);
    printf("%c\n", ch2 + 32);

    return 0;
}

5.typedef自定义

#include <iostream>

typedef int64_t m_long;
typedef char m_char;
typedef uint8_t m_char1;

int main() {
    m_long a = 20;
    printf("%d\n", a);

    m_char b = 'A';
    printf("%c\n", b);

    m_char1 c = 'c';
    printf("%c\n", c);

    return 0;
}