Essentials

Essentials
Accessing keys
resources with 2 keys:
{
    "key": "value of key",
    "look": {
        "deep": "value of look deep"
    }
}
sample
i18next.t('key');
// -> "value of key"
​
i18next.t('look.deep');
// -> "value of look deep"
Passing a default value
You can pass in a default value for cases the key could not be found in translations like:
i18next.t('key', 'default value to show');
In case you're using the saveMissing functionality, it will also pass the defaultValue to your chosen backend, like shown in this React.js example.
Accessing keys in different namespaces
Namespaces are a feature in i18next internationalization framework which allows you to separate translations that get loaded into multiple files.
init
i18next.init({
  ns: ['common', 'moduleA'],
  defaultNS: 'moduleA'
});
moduleA.json
{
    "name": "Module A"
}
common.json
{
    "button": {
        "save": "save"
    }
}
sample
i18next.t('name');
// -> "Module A"
​
i18next.t('common:button.save');
// -> "save"
Multiple fallback keys
Calling the t function with an array of keys enables you to translate dynamic keys providing a non specific fallback value.
As a sample think of an error code you get and you like to show a specific warning in some cases:
keys
{
  "error": {
    "unspecific": "Something went wrong.",
    "404": "The page was not found."
  }
}
sample
// const error = '404';
i18next.t([`error.${error}`, 'error.unspecific']); // -> "The page was not found"
​
// const error = '502';
i18next.t([`error.${error}`, 'error.unspecific']); // -> "Something went wrong"
Overview options
i18next.t(key, options)
option
description
defaultValue
defaultValue to return if a translation was not found, you also can define defaults for plurals by adding defaultValue_plural / defaultValue_2 -> _suffix depends on same pluralrules.
count
count value used for plurals​
context
used for contexts (eg. male / female)
replace
object with vars for interpolation - or put them directly in options
lng
override language to use
lngs
override languages to use
fallbackLng
override language to lookup key if not found see fallbacks for details
ns
override namespaces (string or array)
keySeparator
override char to separate keys
nsSeparator
override char to split namespace from key
returnObjects
accessing an object not a translation string (can be set globally too)
joinArrays
char, eg. '\n' that arrays will be joined by (can be set globally too)
postProcess
string or array of postProcessors to apply see  interval plurals as a sample
interpolation
override interpolation options​
skipInterpolation
skip interpolation and nesting for this call to t function
ignoreJSONStructure
if a key is not found as nested key, it will try to lookup as flat key

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First setup help

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Interpolation

Last updated 5 months ago

option	description
defaultValue	defaultValue to return if a translation was not found, you also can define defaults for plurals by adding defaultValue_plural / defaultValue_2 -> _suffix depends on same pluralrules.
count	count value used for plurals
context	used for contexts (eg. male / female)
replace	object with vars for interpolation - or put them directly in options
lng	override language to use
lngs	override languages to use
fallbackLng	override language to lookup key if not found see fallbacks for details
ns	override namespaces (string or array)
keySeparator	override char to separate keys
nsSeparator	override char to split namespace from key
returnObjects	accessing an object not a translation string (can be set globally too)
joinArrays	char, eg. '\n' that arrays will be joined by (can be set globally too)
postProcess	string or array of postProcessors to apply see interval plurals as a sample
interpolation	override interpolation options
skipInterpolation	skip interpolation and nesting for this call to t function
ignoreJSONStructure	if a key is not found as nested key, it will try to lookup as flat key