I would like to update a variable and array item after a record array search, and wanted to know what would be the best way of carrying it out in Javascript.

In this case, if a match is found between the variable and area item, then the postcode item should be appended to the variable.

The same needs to be done for the array items, but I reckon that a for loop would work best in this scenario, as each individual item would need to be accessed somehow.

Btw due to the nature of my program, there will always be a match. Furthermore, I need to be able to distinguish between the singleAddress and multipleAddresses variables.

Hopefully this code explains things better:

// before search 
var singleAddress = "Mount Farm";
var multipleAddresses = ["Elfield Park", "Far Bletchley", "Medbourne", "Brickfields"];

// this is the record which the search needs to be run against
plot = [{
    postcode: "MK1",
    area: "Denbigh, Mount Farm",
}, {
    postcode: "MK2",
    area: "Brickfields, Central Bletchley, Fenny Stratford, Water Eaton"
}, {
    postcode: "MK3",
    area: "Church Green, Far Bletchley, Old Bletchley, West Bletchley",
}, {
    postcode: "MK4",
    area: "Emerson Valley, Furzton, Kingsmead, Shenley Brook End, Snelshall West, Tattenhoe, Tattenhoe Park, Westcroft, Whaddon, Woodhill",
}, {
    postcode: "MK5",
    area: "Crownhill, Elfield Park, Grange Farm, Oakhill, Knowlhill, Loughton, Medbourne, Shenley Brook End, Shenley Church End, Shenley Lodge, Shenley Wood",
}]

// after search is run then:
// var singleAddress = "Mount Farm, MK1"
// var multipleAddresses = ["Elfield Park, MK5", "Far Bletchley, MK3", "Medbourne, MK5", "Brickfields, MK2"]

convert this to actual code
func(address)
loop object
addr in object[i].area ?
then addr += object[i].postcode
else continue
end

loop for arrays
or make it recursive