Powershell add column name to array data then convert it to JSON - powershell

Question

Basically I formed an array of data based on certain conditions inside a loop and arrary data is something like this:
student1 RL123 S12 student2 RL423 S32 student6 RL166 S02 student34 RL993 P12 student99 RL923 S12
Above array data needs to be converted to JSON as below:
{
"Name" : "student1"
"RollNo" : "RL123"
"SubjectID" : "S12"
},
{
"Name" : "student2"
"RollNo" : "RL423"
"SubjectID" : "S32"
},
{
"Name" : "student6"
"RollNo" : "RL166"
"SubjectID" : "S02"
},
{
"Name" : "student34"
"RollNo" : "RL993"
"SubjectID" : "RL993"
},
{
"Name" : "student99"
"RollNo" : "RL923"
"SubjectID" : "S12"
}

Answer 1

If indeed your array is an array of strings (let's call it $students), you can skip the below line.
However, the way you have formatted it in your question makes it a string with space-separated items, so if that is the case, we should create a proper array from it by splitting on the whitespaces:
$students = 'student1 RL123 S12 student2 RL423 S32 student6 RL166 S02 student34 RL993 P12 student99 RL923 S12' -split '\s+'
Now just iterate over the values in the array and create objects using 3 array elements on each object:
$data = for ($i = 0; $i -lt $students.Count; $i+=3) {
[PsCustomObject]#{
Name = $students[$i]
RollNo = $students[$i + 1]
SubjectID = $students[$i + 2]
}
}
# here you convert the object array to JSON
$data | ConvertTo-Json
Output:
[
{
"Name": "student1",
"RollNo": "RL123",
"SubjectID": "S12"
},
{
"Name": "student2",
"RollNo": "RL423",
"SubjectID": "S32"
},
{
"Name": "student6",
"RollNo": "RL166",
"SubjectID": "S02"
},
{
"Name": "student34",
"RollNo": "RL993",
"SubjectID": "P12"
},
{
"Name": "student99",
"RollNo": "RL923",
"SubjectID": "S12"
}
]
the opening [ and closing ] denote that we're dealing with an array in Json syntax