In the process of developing JavaScript code to pinpoint the smallest unused number within a specified range of numbers, I encountered an issue with the AJAX request. Despite successfully retrieving all used numbers in the designated range, some undefined values are being returned intermittently alongside the accurate data. My comparison of the retrieved values from the JSON response with the contents of the SQL table revealed that all the correct values match between the two sources. Hence, I am baffled as to where these unexpected undefined values originate from.
https://i.stack.imgur.com/KLLXP.jpg
Here is a snippet of the JavaScript code:
//Specified range of numbers to search.
var startRange = 40000;
var endRange = 49999;
//UPC's are padded with to 13 digits with 0's then sent as parameters.
var startUPC = '00000000' + startRange;
var endUPC = '00000000' + endRange;
// AJAX call to web API that gathers all UPC's within a range.
$.ajax({
url: "api/GetNewPLU",
type: "GET",
dataType: "json",
data: { 'startUPC': startUPC, 'endUPC': endUPC },
success: function (data) {
$.each(data.data, function (i, UPCs) {
for (var i in UPCs) {
console.log("UPC: " + UPCs[i].F01);
}
})
},
error: function (error) {
console.log(`Error ${error}`)
}
})
Upon inspecting the JSON Response:
{
"draw": null,
"data": [{
"DT_RowId": "row_0000000040002",
"OBJ_TAB": {
"F01": "0000000040002"
}
}, {
"DT_RowId": "row_0000000040008",
"OBJ_TAB": {
"F01": "0000000040008"
}
}, {
"DT_RowId": "row_0000000040013",
"OBJ_TAB": {
"F01": "0000000040013"
}
}, {
"DT_RowId": "row_0000000040017",
"OBJ_TAB": {
"F01": "0000000040017"
}
}
}
My approach involves iterating through the used numbers obtained via the AJAX request and comparing them with sequentially generated incremented numbers until identifying an unmatched value which will be recorded as the first unused number. At this point, I question whether resolving the mystery of obtaining both valid values and undefined ones is crucial or if simply implementing a filtering mechanism for the undefined values suffices.