13 — Chance: how often out of a hundred

The random number of guide 12 rolls a die, and a die gives all six faces equally often. Chance is different: you decide how often something happens. Thirty times out of a hundred is written 30% chance.

#Steps

1. Type this into the writing box:

   30% chance say You found a coin in the street
   

   copyrun it →

   Run it ten times and it happens about three times. Some days not at all. Korean is:

   30% 확률로 말해줘 길에서 동전을 주웠습니다
   

   copyrun it →

2. To hang several lines on the same chance, write it as a block and close it with end:

   10% chance
       say The sky darkens.
       say Rain comes down.
   end
   

   copyrun it →

3. A decimal point is allowed to one place:

   12.5% chance say This is a rare thing
   

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   Two places are refused when the program is compiled. 12.25% is an error, and it tells you to write something like 12.3% instead. It does not quietly round, because a program must never decide something its author did not write.

   A whole number carries no decimal: 50% is exactly fifty in a hundred. You never need to add .0.

4. A chance can be kept as true or false, so the same result can be used in several places:

   rain is a 40% chance
   if rain
       say Take an umbrella.
   else
       say It is clear today.
   end
   

   copyrun it →

   rain is decided once, when the program reaches that line, and does not change afterwards. Writing 40% chance on two separate lines draws twice, so the two can disagree. When one decision has to hold everywhere, keep it in a name like this.

5. 0% never happens and 100% always does. Both are useful while you are still building: turn a line on and off without deleting it.

   100% chance say This is only a test
   

   copyrun it →

#Try it

Use a die and a chance together. The die decides what, the chance decides how often.

set die to random number from 1 to 6
say Here it comes
say die
20% chance say And a second one rolled out with it

A name you have given a value to becomes that value inside a sentence. So if the second line said You rolled the die, the word die would come out as the number rather than as the word. To print a word as itself, keep the name out of the sentence.

#What you learned

• 30% chance … happens thirty times in a hundred. Korean is 30% 확률로 ….
• Open 30% chance as a block and close it with end to cover several lines.
• One decimal place is allowed; two are refused as an error.
• name is a 30% chance decides once and keeps the answer as true or false.
• 0% is never and 100% is always.