Edit function: delete temperature diff options

- Create a copy of the array passed in as an argument, which will be
modified in place

- Replace 'forEach' method with 'filter' method for brevity

public/js/appChart.js

@@ -179,32 +179,24 @@ const drawChartUsingSelectedOptions = async function () {
         selectedBuildingsDataPointsSamplingRateAbbrevNestedArr
       );
 
-    // Create copies of the arrays of building(s) + data point(s) + sampling rate
-    const selectedBuildingsDataPointsSamplingRateAbbrevRawObsCopyArr = [
-      ...selectedBuildingsDataPointsSamplingRateAbbrevNestedArr,
-    ];
-
-    const selectedBuildingsDataPointsSamplingRateAbbrevTempDiffCopyArr = [
-      ...selectedBuildingsDataPointsSamplingRateAbbrevNestedArr,
-    ];
-
-    // Check if we have raw observations
+    // Check whether we have dT (temperature difference), if so, delete these options,
+    // then compute abbreviations for raw observations
     const selectedBuildingsDataPointsSamplingRateAbbrevRawObsArr =
       checkIfSelectedOptionsContainTemperatureDifference(
-        selectedBuildingsDataPointsSamplingRateAbbrevRawObsCopyArr
+        selectedBuildingsDataPointsSamplingRateAbbrevNestedArr
       )
         ? deleteTemperatureDifferenceOptions(
-            selectedBuildingsDataPointsSamplingRateAbbrevRawObsCopyArr
+            selectedBuildingsDataPointsSamplingRateAbbrevNestedArr
           )
-        : selectedBuildingsDataPointsSamplingRateAbbrevRawObsCopyArr;
+        : selectedBuildingsDataPointsSamplingRateAbbrevNestedArr;
 
     // Check if we have dT (temperature difference)
     const selectedBuildingsDataPointsSamplingRateAbbrevTempDiffArr =
       checkIfSelectedOptionsContainTemperatureDifference(
-        selectedBuildingsDataPointsSamplingRateAbbrevTempDiffCopyArr
+        selectedBuildingsDataPointsSamplingRateAbbrevNestedArr
       )
         ? extractTemperatureDifferenceOptions(
-            selectedBuildingsDataPointsSamplingRateAbbrevTempDiffCopyArr
+            selectedBuildingsDataPointsSamplingRateAbbrevNestedArr
           )
         : [];
 

public/js/src_modules/dropDownListHelpers.mjs

@@ -180,31 +180,28 @@ const getIndexesOfTemperatureDifferenceOptions = function (
 const deleteTemperatureDifferenceOptions = function (
   buildingDataPointSamplingRateAbbrevArr
 ) {
+  // Create a copy of the input array, will be modified in place
+  const buildingDataPointSamplingRateAbbrevCopyArr = [
+    ...buildingDataPointSamplingRateAbbrevArr,
+  ];
+
   // Calculate the index(es) that we wish to delete
   const foundIndexesArr = getIndexesOfTemperatureDifferenceOptions(
-    buildingDataPointSamplingRateAbbrevArr
+    buildingDataPointSamplingRateAbbrevCopyArr
   );
 
   // Delete the index(es) of `dT`, modifies the array in place
   // Note: The resulting array is sparse
   foundIndexesArr.forEach(
-    (foundIndex) => delete buildingDataPointSamplingRateAbbrevArr[foundIndex]
+    (foundIndex) =>
+      delete buildingDataPointSamplingRateAbbrevCopyArr[foundIndex]
   );
 
-  // Array to store our final result
-  const buildingDataPointFinalArr = [];
-
   // Remove the empty sub array(s) that makes entire array sparse
   // Note: `empty` does not mean `undefined` or `null`
-  buildingDataPointSamplingRateAbbrevArr.forEach(
-    (bldgDataPntSmplingRateAbbrvArr) => {
-      if (typeof bldgDataPntSmplingRateAbbrvArr === "object") {
-        buildingDataPointFinalArr.push(bldgDataPntSmplingRateAbbrvArr);
-      }
-    }
+  return buildingDataPointSamplingRateAbbrevCopyArr.filter(
+    (bldgDataPntSamplingRate) => typeof bldgDataPntSamplingRate === "object"
   );
-
-  return buildingDataPointFinalArr;
 };
 
 /**