Ultimate Algorithmic Trading System

FIGURE 4.21
Sample loop programming code.
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INTRODUCTION TO AMIBROKER’S AFL
programmer that certain lines are controlled by a loop or if construct. All the code
involved with the for loop is surrounded by curly brackets. The code controlled
by the if statement is surrounded by nested curly brackets. By matching an opening
left curly bracket with a closing curly right bracket, the programmer can easily see
what code goes with the for loop or the if statement. The left curly bracket right
after the loop definition opens up the block of code consisting of six lines. The lastright
curly bracket closes the loop and the block of code.
In addition to having to use the curly brackets to tell the computer which lines of
code go inside the loop or the if construct, it’s good practice to also indent the lines
of code enclosed within brackets. This is not a necessity, but it makes the readability
of the code so much easier. Now that we are using loops and ifs, we can highlight
the collapsible or folding text feature of the editor. Look at the code in Figure 4.21.
Notice where the arrows for the opening curly brackets are pointing. Now look at
the small boxes with a dash inside that correspond to the curly brackets. If you click
on the first box, the code controlled by the corresponding line of code will collapse
or hide. Go ahead and do it—see for yourself. If you click on the very first box, all
the code disappears except the for loop definition. The second box collapses the
code that goes with the first if. This is a neat feature if you want to streamline the
look of your code, or if you want to hide it and send a screenshot to someone else.
The combination of array and loop programming capabilities in AmiBroker should
facilitate any programming needs you come across.
■ Summary
All programming languages are built on expressions and operators and the precedence
of those operators. A solid understanding of these concepts is absolutely necessary
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