====== Creating a lang file ======
Notice how your item has a weird display name, such as //item.tutorial.my_item//? This is because your item's name doesn't have a translation in your game's selected language. Translations are used to support multiple different languages for a single string.

===== Creating a lang file =====
You can use lang files to provide translations for translatable strings in-game. You'll need to create a file with an appropriate file name for your language-- to find your languages' code, visit [[https://minecraft.wiki/w/Language#Languages|Minecraft Wiki]]. English is en_us. Once you have your language code, create a JSON file at ''resources/assets/modid/lang/''; a full example for an English translation file would be ''resources/assets/tutorial/lang/en_us.json''. 

===== Adding a translation =====
After you've created the lang file, you can use this basic template to add translations:
<code JavaScript resources/assets/tutorial/lang/en_us.json>
{
  "item.tutorial.my_item": "My Item",
  "item.tutorial.my_awesome.item": "My Awesome Item",
  [...]
}
</code>
where the keys in JSON is the translation key. If you're following along in the wiki tutorial, remember to change namespace ''tutorial'' to the namespace you actually use.

===== Using custom translatable text =====
Whenever a function accepts ''<yarn class_2561>'', you have the option of giving it a ''new <yarn class_2585>()'' or ''Text.literal()'' (for versions since 1.19), which means minecraft will use the string in the constructor argument as-is. However, this is not advisable because that would make it difficult to translate that text to another language, should you wish to do that. This is why whenever a ''<yarn class_2561>'' object is needed, you should give it a ''new <yarn class_2588>()'' or ''Text.translatable'' with a translation key, and then translate the key in the lang file. 

For example, when adding a tooltip, do:
<yarncode java>
@Override
public void method_9568(ItemStack stack, TooltipContext context, List<Text> tooltip, TooltipType type) {
    // 1.18.2 and before
    tooltip.add(new class_2588("item.tutorial.fabric_item.tooltip"));
    
    // 1.19 and later
    tooltip.add(Text.translatable("item.tutorial.fabric_item.tooltip"));
}
</yarncode>

And then add in the lang file:
<code JavaScript resources/assets/tutorial/lang/en_us.json>
{
  "item.tutorial.fabric_item.tooltip": "My Tooltip"
}
</code>

And the tooltip will be displayed as "My Tooltip"!

===== Adding dynamic values to translatable text =====
Say you want the text to change based on some variable, like the current day and month. For a dynamic number, we put a ''%s'' where you want the number to show in the lang entry value, for example:
<code JavaScript resources/assets/tutorial/lang/en_us.json>
{
  "item.tutorial.fabric_item.tooltip": "My Tooltip in day %s, and month %s" 
}
</code>
Then we pass the variables we use in our string by the order it appears in the text. First the day, then the month:
<yarncode java>
int currentDay = 4;
int currentMonth = 7;

// 1.18.2 and before:
tooltip.add(new class_2588("item.tutorial.fabric_item.tooltip", currentDay, currentMonth));

// 1.19 and later:
tooltip.add(Text.translatable("item.tutorial.fabric_item.tooltip", currentDay, currentMonth));
</yarncode>

In translations, the order of variables may change. Therefore, you can explicitly specify the index of variables by using something like ''%1$s'' and ''%2$s''.

If you want for it to literally show ''%'', use ''%%''.

For more information, see [[https://dzone.com/articles/java-string-format-examples|Java String.format]] (it works the same way).

==== Adding a new line ====
The line-break ''\n'' work finely in command outputs. However in many cases, such as item tooltips, they may not workd correctly. So in order to have a string with multiple lines in the tooltip, you must split the translation key into multiple keys:
<code JavaScript resources/assets/tutorial/lang/en_us.json>
{
  "item.tutorial.fabric_item.tooltip_1": "Line 1 of my tooltip", 
  "item.tutorial.fabric_item.tooltip_2": "Line 2 of my tooltip" 
}
</code>
Then add the ''<yarn class_2588>'' parts individually:
<yarncode java>
// 1.18.2 and below:
tooltip.add(new class_2588("item.tutorial.fabric_item.tooltip_1"));
tooltip.add(new class_2588("item.tutorial.fabric_item.tooltip_2"));

// 1.19 and later
tooltip.add(Text.translatable("item.tutorial.fabric_item.tooltip_1"));
tooltip.add(Text.translatable("item.tutorial.fabric_item.tooltip_2"));
</yarncode>
And the tooltip will be displayed as:

<yarncode>
Line 1 of my tooltip
Line 2 of my tooltip
</yarncode>