for Loop

for loop #

The for loop serves the same purpose as the while loop. for makes it possible to put the definitions and expressions concerning the loop’s iteration on the same line.
Although for is used much less than foreach in practice, it is important to understand the for loop first. We will see foreach in a later chapter.

The sections of the while loop #

The while loop evaluates the loop condition and continues executing the loop as long as that condition is true. For example, a loop to print the numbers between 1 and 10 may check the condition less than 11. To be compilable as D code, number must have been defined before its first use:

int number = 1;
while (number < 11)

Iterating the loop can be achieved by incrementing the number at the end of the loop:

++number;

Finally, there is the actual work within the loop body:

writeln(number);

These four sections can be combined into the desired loop as follows: