Array difference

Anatomy

<array:diff var="var" var_set="var" var_result="(destructive on 'var')" type="values"/>

Description: ARRAY:DIFF generates the symmetric difference of two arrays by merging those items of both arrays that do not exist within both arrays together, whereas duplicated non-numeric keys are overwritten while items with numeric keys are appended.

Attention:

ARRAY:DIFF is destructive, in the sense that it modifies the array in-place, unless 'var_result' is specified in which case a copy of the resulting array will be stored in 'var_result' instead. It partially preserves the key and value associations of the array.

Attributes

Name	Type	Description	Defined By
var	var	Variable name	array:diff
var_set	var	Set variable name	array:diff
var_result	var	Result variable name	array:diff
type	type	Difference type	array:diff

Results:

Binding	Type	Predicate
var	var_result	array

Examples

Difference by keys

<array var="names">
  <item key="bg">Bill Gates</item>
  <item key="sj">Steve Jobs</item>
</array>

<array var="diff">
  <item key="sj">Steve Jobs</item>
  <item key="le">Larry Ellison</item>
</array>

<array:diff var="names" var_set="diff" type="keys"/>
<output>$names.bg and $names.le are competitors!</output>

<!-- Bill Gates and Larry Ellison are competitors! -->

Difference by values

<array var="names">
  <item>Bill Gates</item>
  <item>Steve Jobs</item>
</array>

<array var="diff">
  <item>Steve Jobs</item>
  <item>Larry Ellison</item>
</array>

<array:diff var="names" var_set="diff" type="values"/>
<output>$names[0] and $names[1] are competitors!</output>

<!-- Bill Gates and Larry Ellison are competitors! -->