collections.Merge

Returns a map by combining two or more given maps.

Syntax: collections.Merge MAP MAP...
Returns: map[string]any
Alias: merge

Returns the result of merging two or more maps from left to right. If a key already exists, merge updates its value. If a key is absent, merge inserts the value under the new key.

Key handling is case-insensitive.

The following examples use these map definitions:

{{ $m1 := dict "x" "foo" }}
{{ $m2 := dict "x" "bar" "y" "wibble" }}
{{ $m3 := dict "x" "baz" "y" "wobble" "z" (dict "a" "huey") }}

This example merges $m1, $m2, and $m3, in that order:

{{ $merged := merge $m1 $m2 $m3 }}

{{ $merged.x }}   → baz
{{ $merged.y }}   → wobble
{{ $merged.z.a }} → huey

This example merges $m3, $m2, and $m1, in that order:

{{ $merged := merge $m3 $m2 $m1 }}

{{ $merged.x }}   → foo
{{ $merged.y }}   → wibble
{{ $merged.z.a }} → huey

This example merges $m2, $m3, and $m1, in that order:

{{ $merged := merge $m2 $m3 $m1 }}

{{ $merged.x }}   → foo
{{ $merged.y }}   → wobble
{{ $merged.z.a }} → huey

This example merges $m1, $m3, and $m2, in that order:

{{ $merged := merge $m1 $m3 $m2 }}

{{ $merged.x }}   → bar
{{ $merged.y }}   → wibble
{{ $merged.z.a }} → huey

Regardless of depth, merging only applies to maps. For slices, use the collections.Append function.

Last updated: September 11, 2026 : content: Comply with function/method description guidance in style guide (76fa3fc9e)

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