Filter JSON based on the user input powershell

Question

I have user input which is separated by commas and I am using split function to get different values. I have an API that returns some data in JSON. I want to filter data from API Json based on the user input

Powershell code

#Get Input data
$GetIds = Read-Host -Prompt 'Enter Ids:'

#Example 1,2
#If they enter 1,2, I want results data of John and Mark
#API Call Data
$json = @'
{  
    "results": [
        {
            "id": "1", 
             "name": "John",           
        }, 
        {
             "id": "2", 
             "name": "Mark",  
        },
        {
             "id": "3", 
             "name": "Rachel",  
        }
    ]
}
'@

$Obj = ConvertFrom-Json $json

#Split by comma

$userInputData = -split $GetIds 

#Filter json with $userInputData 
$FilteredData = $json | Where-Object { $_.id -eq #loop through $userInputData }

I want the filtered data to return $json filtered by the userInput data. Thank you

Answer 1

First, use the binary form of the -split operator if you want to split by commas (,) - the unary form splits by whitespace only.

# Sample user input
$GetIds = '1, 2'

# Split by ",", remove surrounding whitespace, convert to integers.
# For brevity, there's no error handling her, 
# so an empty / blank input wouldn't be interpreted as id 0, 
# and input such as `'1 2'` (no comma) would break.
[int[]] $userInputData = ($GetIds -split ',').Trim()

Next, it is $Obj that you must filter with Where-Object, i.e. the custom-object graph that ConvertFrom-Json parsed your JSON text into, not the raw JSON:

$filteredData = $Obj.results | Where-Object id -in $userInputData

The -in operator allows you to test the LHS for being part of the RHS array.

---

To put it all together:

Note: Your sample JSON is technically invalid, due to trailing commas after the last property in the .results objects, which I've corrected below. In PowerShell [Core] v6+, ConvertFrom-Json would accept even the invalid JSON, but not in Windows PowerShell.

# Sample user input, in lieu of the Read-Host call.
$GetIds = '1, 2'

# Split by ",", remove surrounding whitespace, convert to integers.
# For brevity, there's no error handling her, 
# so an empty / blank input wouldn't be interpreted as id 0, 
# and input such as `'1 2'` (no comma) would break.
[int[]] $userInputData = ($GetIds -split ',').Trim()

$Obj = ConvertFrom-Json @'
{  
    "results": [
        {
            "id": "1", 
             "name": "John"
        }, 
        {
             "id": "2", 
             "name": "Mark"
        },
        {
             "id": "3", 
             "name": "Rachel"
        }
    ]
}
'@

$filteredData = $Obj.results | Where-Object id -in $userInputData

# Output the matching objects
$filteredData

The above yields:

id name
-- ----
1  John
2  Mark

Answer 2

How about...

# You can split on the read
$GetIds = (Read-Host -Prompt 'Enter Ids') -split (',')
# Results
<#
1
2
#>

# Your JSON string was not valid
<#
Error: Parse error on line 4:
...     "name": "John",     },      {           "id": "2",
----------------------^
Expecting 'STRING', got '}'
#>

# Corrected, notice the removed comma after the names 
$json = @'
{  
    "results": [
        {
            "id": "1", 
             "name": "John"           
        }, 
        {
             "id": "2", 
             "name": "Mark"  
        },
        {
             "id": "3", 
             "name": "Rachel"  
        }
    ]
}
'@

$Obj = $json | ConvertFrom-Json

No need for this...

$userInputData = -split $GetIds 

... since the split is on the Read

# Filter json with $userInputData 
$Obj.results | 
Where-Object id -in $GetIds
# Results
<#
id name
-- ----
1  John
2  Mark
#>