--- title: collections.NewScratch description: Returns a locally scoped "scratch pad" to store and manipulate data. categories: [] keywords: [] params: functions_and_methods: aliases: [newScratch] returnType: maps.Scratch signatures: [collections.NewScratch ] --- Use the `collections.NewScratch` function to create a locally scoped [scratch pad](g) to store and manipulate data. To create a scratch pad with a different [scope](g), refer to the [scope](#scope) section below. ## Methods ### Set Sets the value of the given key. ```go-html-template {{ $s := newScratch }} {{ $s.Set "greeting" "Hello" }} ``` ### Get Gets the value of the given key. ```go-html-template {{ $s := newScratch }} {{ $s.Set "greeting" "Hello" }} {{ $s.Get "greeting" }} → Hello ``` ### Add Adds the given value to existing value(s) of the given key. For single values, `Add` accepts values that support Go's `+` operator. If the first `Add` for a key is an array or slice, the following adds will be appended to that list. ```go-html-template {{ $s := newScratch }} {{ $s.Set "greeting" "Hello" }} {{ $s.Add "greeting" "Welcome" }} {{ $s.Get "greeting" }} → HelloWelcome ``` ```go-html-template {{ $s := newScratch }} {{ $s.Set "total" 3 }} {{ $s.Add "total" 7 }} {{ $s.Get "total" }} → 10 ``` ```go-html-template {{ $s := newScratch }} {{ $s.Set "greetings" (slice "Hello") }} {{ $s.Add "greetings" (slice "Welcome" "Cheers") }} {{ $s.Get "greetings" }} → [Hello Welcome Cheers] ``` ### SetInMap Takes a `key`, `mapKey` and `value` and adds a map of `mapKey` and `value` to the given `key`. ```go-html-template {{ $s := newScratch }} {{ $s.SetInMap "greetings" "english" "Hello" }} {{ $s.SetInMap "greetings" "french" "Bonjour" }} {{ $s.Get "greetings" }} → map[english:Hello french:Bonjour] ``` ### DeleteInMap Takes a `key` and `mapKey` and removes the map of `mapKey` from the given `key`. ```go-html-template {{ $s := newScratch }} {{ $s.SetInMap "greetings" "english" "Hello" }} {{ $s.SetInMap "greetings" "french" "Bonjour" }} {{ $s.DeleteInMap "greetings" "english" }} {{ $s.Get "greetings" }} → map[french:Bonjour] ``` ### GetSortedMapValues Returns an array of values from `key` sorted by `mapKey`. ```go-html-template {{ $s := newScratch }} {{ $s.SetInMap "greetings" "english" "Hello" }} {{ $s.SetInMap "greetings" "french" "Bonjour" }} {{ $s.GetSortedMapValues "greetings" }} → [Hello Bonjour] ``` ### Delete Removes the given key. ```go-html-template {{ $s := newScratch }} {{ $s.Set "greeting" "Hello" }} {{ $s.Delete "greeting" }} ``` ### Values Returns the raw backing map. Do not use with `Store` methods on a `Page` object due to concurrency issues. ```go-html-template {{ $s := newScratch }} {{ $s.SetInMap "greetings" "english" "Hello" }} {{ $s.SetInMap "greetings" "french" "Bonjour" }} {{ $map := $s.Values }} ``` {{% include "_common/scratch-pad-scope.md" %}}