(C++)++ Course

The else Statement

2/8

Nested if statements are things that I use a lot. There are just some times when an AND operator just isn't the right fit. A nested if statement, to me, is said like this: 'If this and then for this case, this.'

//if this
if (mark >= 50) {
    //and then for this case (over or equal to 50)
    if (mark == 100) {
        cout << "Perfect!" << endl;
    }
}

Also, sometimes you might need to check several conditions that may not be directly related. For example, say I have an object with an x and y postion. Checking x is not directly related to y, but you still need to check both. For cases like these, using two if statements without using an else statement on either is the best way to do it.

if (xPosition > width) {
    //do something
}
if (yPosition > height) {
    //do something
}

The while loop

3/8

In SoloLearn's course examples, they tend to use while loops for counting things, which is certainly fine, but is not exactly the best use of a while loop, in my experience. In a while loop, you should really be waiting for something to happen. Most frequently, I have used the while loop for a game loop where I'm waiting until I am dead or the game is won. It can also be useful for finding things in an array or grid.

Using a while loop

4/8

Like I said in the last section, while loops used in this section can be, and should be, replaced with for loops, which they use in the next section. I just wish they had done the for loops first, so that the while loops weren't used as bad for loops, because while loops certainly have their place in C++ - for when you're not sure how many loops it's going to take.

The for Loop

5/8

The for loop is very powerful. At the end of the SL course for this section, they mention that you can change the increment from a++ to something like a += 5. What they don't tell you is that you can add multiple variables into each section of the for loop; just use a comma to separate them:

for (int i = 0, j = 2; i < 3; i++, j--) {
    cout << i << ", " << j << endl;
}

0, 2
1, 1
2, 0

You can add as many as you want as well. As you can see, you don't need to use each variable in every section of the foor loop either. In fact, for the conditional (middle section) adding more than one is risky. All conditions within the conditional statement must evaluate to false for the loop to stop.

The switch Statement

6/8

The switch statement is also a powerful tool when used correctly. In the SL course, they strictly use integers within their switch statement, but you can also use characters:

char ch = 'a';
switch (ch) {
case 'a':
    cout << "This is a.\n"
    break;//outputs This is a
}

You can also use enumerations, which is a much more advanced technique.

enum class Fruits {
    apple,
    orange,
    grape
};
Fruits fruit = Fruits::apple;

switch (fruit) {
case Fruits::apple:
    cout << "Apple\n";
    break;
default:
    cout << "Not apple\n";
}//outputs Apple

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