Изучение Си в одном видео уроке за час!

// Условные операторы
int age;
    
printf ("Enter your age: ");
scanf ("%d", &age);

if (age > 18) {
    printf("Your age is bigger than 18. Age is %d
", age);
    if (age == 21)
        printf ("Age is 21");
} else if (age < 18) {
    printf("Your age is less than 18. Age is %d
", age);
} else {
    printf("Your age is equal 18. Age is %d
", age);
}

int x = 2, y = 4;
int c;
    
c = x > y ? 23 : 45;
printf ("%d", c);

// Switch case
int res;
scanf ("%d", &res);

switch (res) {
    case 1:
        printf ("Variable %d", res);
        break;
    case 245:
        printf ("Variable is 245");
        break;
    case 10:
        printf ("Variable is %d", res);
        break;
    case 678:
        printf ("Variable is very big - %d", res);
        break;
    default:
        printf ("Some other number");
}

printf ("
");

// Циклы
int i = 100;

do {
    printf ("i is %d", i);
} while (i < 10);

int i = 200;

while (i < 10) {
    printf ("i is %d
", i);
    i /= 2;
}

for (int i = 100; i > 0; i /= 2) {
    printf ("i is %d
", i);
}

// Функции
void print (float number) {
    printf ("Your number is %.2f
", number);
}

float del (float a, float b) {
    float res;
    if (b != 0)
        res = a / b;
    else
        res = 0;
    return res;
}

int main () {
    int num_1, num_2;
    scanf("%d", &num_1);
    scanf("%d", &num_2);
    float result = del (num_1, num_2);
    print (result);
    
    
    return 0;
}

// Массивы
char array [5] = {'H', 'e', 'l', 'l', 'o'};
char arr[] = "Hello";
int nums [3] = {23, 56, 12};
nums [2] = 456;
printf ("element is %d
", nums[2]);

for (int i = 0; i < 5; i++) {
    printf ("%c", arr[i]);
}

printf ("
");

// Двумерные массивы
int nums [3][2] = {{4, 98}, {89, 23}, {43, 9}};
    
for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 2; j++) {
        printf ("%d    ", nums[i][j]);
    }
    printf ("
");
}

printf ("
");

// Указатели
void getValue (int *my_pointer) {
    *my_pointer = 1000;
}

int main () {
    
    int get_value;
    getValue(&get_value);
    printf ("Value of variable is %d
", get_value);
    
    return 0;
}

// Структуры
struct student {
    int id;
    float percentage;
    char name;
};

int main () {
    
    struct student maks;
    maks.id = 1;
    maks.percentage = 23.4;
    maks.name = 'M';
    
    struct student oleg;
    oleg.name = 'O';
    oleg.id = 2;
    oleg.percentage = 98.8;
    
    printf("Maks id is %d
", maks.id);
    printf("Oleg id is %d
", oleg.id);
    
    return 0;
}