Here is a better example, which uses a comma-delimited list of the JSON elements that should be numeric.
0010 BEGIN
0020 LET arr$["string"]="123"
0030 LET arr$["numeric"]="123",withnum$+="numeric,"
0040 LET arr$["this.is.a.string"]="456"
0050 LET arr$["this.is.a.number"]="456",withnum$+="this.is.a.number,"
0060 PRINT "Withnum$= ",withnum$
0070 PRINT DIM(LIST EDIT arr${ALL} WITH NUM(withnum$))
run
Withnum$= numeric,this.is.a.number,
{
"string":"123",
"numeric":123,
"this":{
"is":{
"a":{
"string":"456",
"number":456
}
}
}
}