The increment (++) and decrement (--) operators have the highest precedence among all operators in C, followed by unary operators, then multiplicative, additive, and so on.

The while loop starts with i=0. It prints 0, then increments i to 1, prints 1, increments to 2, prints 2, increments to 3, and the condition i<3 becomes false, so the loop terminates. Output: 0 1 2

The free() function is used to deallocate memory that was previously allocated using malloc(), calloc(), or realloc(). This prevents memory leaks.

This declaration creates a pointer to an integer and initializes it to NULL, which means it doesn't point to any valid memory address. This is a safe initialization practice.

Since both 5 and 2 are integers, integer division is performed: 5/2 = 2. The %f format specifier then prints this integer value (2) as a floating-point number: 2.000000

The sizeof() operator returns the size in bytes of a data type or variable. For example, sizeof(int) typically returns 4 on most 32-bit systems.

In C, the modulus operator (%) returns a remainder that has the same sign as the dividend. For example, -7 % 3 = -1 (not 2), because -7 is the dividend and it's negative.

A pointer is a variable that stores the memory address of another variable. You can access the value at that address using the dereference operator (*), and pointers can point to any data type.

Both 'const int x = 10;' and 'int const x = 10;' are valid ways to declare a constant in C. The const keyword can be placed before or after the type specifier, and both have the same meaning.

The loop executes for i=0, i=1, and i=2. When i=3, the break statement is encountered, which immediately terminates the loop. Therefore, the loop executes exactly 3 times.