For Loop

If you want to execute the code a certain number of times use the for loop.

Syntax:

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for (statement#1; statement#2; statement#3) {
    // The code block
}

It looks a bit difficult but let’s understand what is actually going on:

• The statement#1 is an initial statement. It is executed at the beginning of for loop and doesn’t repeat later.

• The statement#2 is the condition. The code block in the loop is executed if the condition is true (for example x < 4).

• The statement#3 is executed every time after the code block execution (in most cases it’s this statement increment/decremant the control variable of the loop).

The loop body stops execution if the condition (statement#2) is false.

Let’s look at the example:

This code prints numbers from 1 to 4. Firstly the code sets in the variable x the value 1 before the loop starts. Then we mention that the program should execute the block while the x is less than 5 (x<5) and increment it by 1 every time after the code block execution.

You can also change statements in any convenient way. For example, we want to print all even numbers descending from 10 to 0:

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for (int x = 10; x >= 0; x-=2) {
    cout << x << endl;
}