How SharePoint JSON Script look other column - json

Question

I was looking for a way if JSON Script can look other column and format other column. base on the value of the other column.
Is there an alternate way to use "#currentfield"?
Thanks

Answer 1

Check the Apply formatting based on date ranges demo.
{
"elmType": "div",
"txtContent": "#currentField",
"style": {
"color": {
"operator": "?",
"operands": [
{
"operator": "<=",
"operands": [
"[$DueDate]",
"#now"
]
},
"#ff0000",
""
]
}
}
}

Answer 2

The MS Docs link #Lee_MSFT provided has some decent examples on formatting. In addition to the notes on internal/field names in the discussion on date ranges, the doc includes instructions for cross-referencing other columns (https://learn.microsoft.com/en-us/sharepoint/dev/declarative-customization/column-formatting#fieldname). Essentially, if you want to reference/use data from column A to format column B, you will need to use the "internal name" of column A in the JSON formatting on column B. A column name may be (and often is) different than the "display name" of the column. For example, we have a basic list for tracking some team members:
"Alias/Logon" (SLOT); internal name: Title
"First Name" (SLOT); internal name: FirstName
"Last Name" (SLOT); internal name: LastName
"Current Contracts" (SLOT); internal name: CurrentContracts
We want "Current Contracts" to be a URL link that uses the "Alias/Logon" value and we also want to display an icon. In fact, this column doesn't even require content as it will show an actual icon and the word "Contracts" for all users. Obviously, if you reference a column that is not mandatory, you should do some data validation to ensure you aren't creating bad URLs, etc.
{
"$schema": "https://developer.microsoft.com/json-schemas/sp/column-formatting.schema.json",
"elmType": "a",
"attributes": {
"target": "_blank",
"iconName": "BulletedList",
"class": "sp-field-quickActions",
"href": {
"operator": "+",
"operands": [
"https://mycompany.sharepoint.com/teams/coolpeople/contracts/",
"[$Title]"
]
}
},
"txtContent": "Contracts"
}
Note: just do a search for "SharePoint JSON column formatting" to find a plethora of examples, including the repo on GitHub (https://github.com/SharePoint/sp-dev-list-formatting).