一、隐式类型转换

二、整型提升

2.1 有符号、无符号整型提升

2.2 例子

int main()
{
    char a = 0xb6;
    short b = 0xb600;
    int c = 0xb6000000;
    if(a==0xb6)
    printf("a");
    if(b==0xb600)
    printf("b");
    if(c==0xb6000000)
    printf("c");
    return 0;
}

int main()
{
    char c = 1;
    printf("%u\n", sizeof(c));  //1
    printf("%u\n", sizeof(+c)); //4
    printf("%u\n", sizeof(-c)); //4
    printf("%u\n", sizeof(!c)); //4
    return 0;
}

三、算数转换