Datatype map: Query array values using "for-each" - json

Question

I am looking to extract values from an array where each array is connected to a object key name.
The problem I encounter is not knowing how to structure the inner "xsl:foreach" toward a map array.
I will later differentiate the elements by adding attributes but I left that out to keep the question and data at minimal level.
JSON:
<data>
{
"datasheets": {
"balance": {
"cash": [4, 2, 3, 1],
"bank": [5, 8, 7, 9]
}
}
}
</data>
XSL:
<?xml version="1.0" encoding="UTF-8"?>
<xsl:transform version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:docroot="http://www.example.org/1"
xmlns:report="http://www.example.org/2"
xmlns:cells="http://www.example.org/3"
expand-text="yes"
>
<xsl:output method="xml" indent="yes"/>
<xsl:mode on-no-match="shallow-skip"/>
<!-- Parse JSON to XML -->
<xsl:template match="data">
<docroot>
<xsl:apply-templates select="json-to-xml(.)/*"/>
</docroot>
</xsl:template>
<!-- Transform balance data -->
<xsl:template match="*[#key = 'balance']">
<report:yearly-values>
<xsl:for-each select="./*">
<!-- <xsl:for-each select="./*"> -->
<xsl:element name="cells:{#key}">Placeholder</xsl:element>
<!-- </xsl:for-each> -->
</xsl:for-each>
</report:yearly-values>
</xsl:template>
</xsl:transform>
Result:
<?xml version="1.0" encoding="UTF-8"?>
<docroot xmlns:cells="http://www.example.org/3"
xmlns:docroot="http://www.example.org/1"
xmlns:report="http://www.example.org/2">
<report:yearly-values>
<cells:cash>Placeholder</cells:cash>
<cells:bank>Placeholder</cells:bank>
</report:yearly-values>
</docroot>
Wanted result:
<?xml version="1.0" encoding="UTF-8"?>
<docroot xmlns:cells="http://www.example.org/3"
xmlns:docroot="http://www.example.org/1"
xmlns:report="http://www.example.org/2">
<report:yearly-values>
<cells:cash>4</cells:cash>
<cells:cash>2</cells:cash>
<cells:cash>3</cells:cash>
<cells:cash>1</cells:cash>
<cells:bank>5</cells:bank>
<cells:bank>8</cells:bank>
<cells:bank>7</cells:bank>
<cells:bank>9</cells:bank>
</report:yearly-values>
</docroot>

Answer 1

When you first take this debugging step to see what is going on:
<xsl:template match="*[#key = 'balance']">
<report:yearly-values>
<xsl:copy-of select="."/>
</report:yearly-values>
</xsl:template>
Would give this xml-fragment:
<report:yearly-values>
<map xmlns="http://www.w3.org/2005/xpath-functions" key="balance">
<array key="cash">
<number>4</number>
<number>2</number>
<number>3</number>
<number>1</number>
</array>
<array key="bank">
<number>5</number>
<number>8</number>
<number>7</number>
<number>9</number>
</array>
</map>
</report:yearly-values>
Then it is more clear what you need. Take the for-each one level deeper and use the #key of the parent for you element-name, like this:
<xsl:template match="*[#key = 'balance']">
<report:yearly-values>
<xsl:for-each select="*/*">
<xsl:element name="cells:{parent::*/#key}"><xsl:value-of select="text()"/></xsl:element>
</xsl:for-each>
</report:yearly-values>
</xsl:template>

Answer 2

You're just iterating over the two arrays but not the content of the arrays. The following will produce the wanted output:
<xsl:for-each select="./*/*">
<!-- <xsl:for-each select="./*/*"> -->
<xsl:element name="cells:{parent::*/#key}">
<xsl:value-of select="."/>
</xsl:element>
<!-- </xsl:for-each> -->
</xsl:for-each>