Program Flow

Remember the Program Flow part we have discussed in the Machine code (Assembly) Instruction Set? Here, our Program Flow can be divided into three parts

1. Branching (Conditionals)

2. Repetition (Loops)

3. Abstraction (functions)

Conditionals

Change program flow based on Boolean.

if (a < b)
{
    // do something
}
else
{
    // do something else
}

Loops

Repeat Lines. In C, we have three types of loops, for, while and do-while loops.

An interesting Question

What number is stored in variable b?

int a = 100;
while ((a >= 0) || (a % 2)) {
    a--;
}
int b = a;

This problem is a bit tricky since it utilizes the short-circuiting property of the || operator in C, that is a || b, if a is already true, we won't go to statement b. So, in this problem, we will always enter a >= 0 until a is -1. Then we evaluate a % 2, which will be -1. (In C, every non-zero value is treated as true, so a-- will still be executed and now our a is -2) Then we will exit the loop, so our final value for b will be -2.