C Operators and Expressions

1#include <stdio.h>
2
3int main() {
4    int a = 17, b = 5;
5    
6    printf("a = %d, b = %d\n\n", a, b);
7    printf("a + b = %d\n", a + b);   // 22
8    printf("a - b = %d\n", a - b);   // 12
9    printf("a * b = %d\n", a * b);   // 85
10    printf("a / b = %d\n", a / b);   // 3 (integer division)
11    printf("a %% b = %d\n", a % b);  // 2 (remainder)
12    
13    // Pre vs Post increment
14    int x = 5;
15    printf("\nx = %d\n", x);
16    printf("x++ = %d\n", x++);  // Prints 5, then x becomes 6
17    printf("Now x = %d\n", x);  // x is now 6
18    printf("++x = %d\n", ++x);  // x becomes 7, then prints 7
19    
20    return 0;
21}

1#include <stdio.h>
2
3int main() {
4    int a = 10, b = 5;
5    
6    printf("a = %d, b = %d\n\n", a, b);
7    printf("a == b: %d\n", a == b);  // 0 (false)
8    printf("a != b: %d\n", a != b);  // 1 (true)
9    printf("a > b:  %d\n", a > b);   // 1 (true)
10    printf("a < b:  %d\n", a < b);   // 0 (false)
11    printf("a >= b: %d\n", a >= b);  // 1 (true)
12    printf("a <= b: %d\n", a <= b);  // 0 (false)
13    
14    return 0;
15}

1#include <stdio.h>
2
3int main() {
4    int a = 1, b = 0;  // 1 = true, 0 = false
5    
6    printf("a = %d (true), b = %d (false)\n\n", a, b);
7    
8    // AND: both must be true
9    printf("a && b = %d\n", a && b);  // 0 (false)
10    printf("a && a = %d\n", a && a);  // 1 (true)
11    
12    // OR: at least one must be true
13    printf("a || b = %d\n", a || b);  // 1 (true)
14    printf("b || b = %d\n", b || b);  // 0 (false)
15    
16    // NOT: reverse the value
17    printf("!a = %d\n", !a);  // 0 (false)
18    printf("!b = %d\n", !b);  // 1 (true)
19    
20    // Practical example
21    int age = 25;
22    int hasLicense = 1;
23    if (age >= 18 && hasLicense) {
24        printf("\nYou can drive!\n");
25    }
26    
27    return 0;
28}

1#include <stdio.h>
2
3int main() {
4    int a = 5, b = 3;  // 5 = 0101, 3 = 0011
5    
6    printf("a = %d (0101), b = %d (0011)\n\n", a, b);
7    
8    printf("a & b  = %d\n", a & b);   // 1 (0001)
9    printf("a | b  = %d\n", a | b);   // 7 (0111)
10    printf("a ^ b  = %d\n", a ^ b);   // 6 (0110)
11    printf("~a     = %d\n", ~a);      // -6 (inverts all bits)
12    
13    // Shift operators
14    printf("\na << 1 = %d\n", a << 1);  // 10 (multiply by 2)
15    printf("a << 2 = %d\n", a << 2);    // 20 (multiply by 4)
16    printf("a >> 1 = %d\n", a >> 1);    // 2 (divide by 2)
17    
18    return 0;
19}

1#include <stdio.h>
2
3int main() {
4    int x = 10;
5    printf("Initial x = %d\n\n", x);
6    
7    x += 5;   printf("x += 5  → x = %d\n", x);  // 15
8    x -= 3;   printf("x -= 3  → x = %d\n", x);  // 12
9    x *= 2;   printf("x *= 2  → x = %d\n", x);  // 24
10    x /= 4;   printf("x /= 4  → x = %d\n", x);  // 6
11    x %= 4;   printf("x %%= 4  → x = %d\n", x); // 2
12    
13    return 0;
14}

1#include <stdio.h>
2
3int main() {
4    // sizeof - get size in bytes
5    printf("sizeof(int): %zu bytes\n", sizeof(int));
6    printf("sizeof(char): %zu byte\n", sizeof(char));
7    
8    // Ternary operator (condition ? if_true : if_false)
9    int a = 10, b = 20;
10    int max = (a > b) ? a : b;
11    printf("\nMax of %d and %d is %d\n", a, b, max);
12    
13    // Address-of operator
14    int x = 42;
15    printf("\nValue of x: %d\n", x);
16    printf("Address of x: %p\n", (void*)&x);
17    
18    // Type casting
19    int num = 7;
20    printf("\n7 / 2 = %d (int)\n", num / 2);
21    printf("7 / 2 = %.2f (float)\n", (float)num / 2);
22    
23    return 0;
24}

1#include <stdio.h>
2
3int main() {
4    int a = 10, b = 5;
5    float pi = 3.14, r = 2.0;
6    
7    // Constant expression (evaluated at compile time)
8    int size = 5 + 3 * 2;  // 11
9    printf("Constant: 5 + 3 * 2 = %d\n", size);
10    
11    // Arithmetic expression
12    int sum = a + b * 2;   // 10 + 10 = 20
13    printf("Arithmetic: a + b * 2 = %d\n", sum);
14    
15    // Floating expression
16    float area = pi * r * r;  // 3.14 * 4 = 12.56
17    printf("Floating: pi * r * r = %.2f\n", area);
18    
19    // Relational expression (returns 0 or 1)
20    int isGreater = a > b;  // 1 (true)
21    printf("Relational: a > b = %d\n", isGreater);
22    
23    // Logical expression
24    int bothPositive = (a > 0) && (b > 0);  // 1 (true)
25    printf("Logical: (a > 0) && (b > 0) = %d\n", bothPositive);
26    
27    // Assignment expression (returns assigned value)
28    int x, y;
29    x = (y = 5) + 3;  // y=5, x=8
30    printf("Assignment: x = (y = 5) + 3 → x=%d, y=%d\n", x, y);
31    
32    // Comma expression (evaluates left-to-right, returns last)
33    int result = (a = 1, b = 2, a + b);  // result = 3
34    printf("Comma: (a=1, b=2, a+b) = %d\n", result);
35    
36    return 0;
37}