For Beginners

Lesson 19/23

What If?

What if you wanted to check whether a given condition is met? For instance, you have a for loop and you want to know, when the counter reached a specified value. You can do that easily with the if command:

for ♥i from 1 to 5
  if ♥i==3
    dialog ‴Three was reached‴
  dialog ♥i

The if command is a block command: when a condition is met — the ♥i counter equals 3 in this particular case — the code between the if and the end commands is executed. If a condition is not met, the code in the ifend block is skipped.

In the script above the for loop counts from 1 to 5, and in its each iteration the robot checks, if the ♥i counter equals 3. If it does, the message “Three was reached” is displayed in a dialog box. If it doesn’t, the robot does what it would do anyway, regardless of the condition test result: displays the current counter value.

Note: When setting up a condition that equals a given value, remember to put two equals signs and no spaces (if ♥i==3) — otherwise, the spaces will be treated as separators between another sets of arguments and their values.

In the next lesson you’ll see how to implement alternative conditions.