I have an array of numbers that I want to sort from highest to lowest and still be able to keep the original array to reference the original indexes.
I have managed to accomplish what I want with the code here:
// Original array.
const originalArray = [3, 8, 2, 8, 6, 9, 8, 4];
// Creating a deep copy of an original array.
const deepCopy = [...originalArray].sort(function(a, b){
return b-a
});
// result array
const arr = [];
// count to get the index based on duplicate values.
let count = 0;
// Iterating deepCopy array to get the actual index.
deepCopy.forEach((elem) => {
// Checking for duplicate value in an array
if(originalArray.indexOf(elem) === originalArray.lastIndexOf(elem)) {
// This line of code execute if there is no duplicates in an array.
arr.push(originalArray.indexOf(elem))
}else{
// This line of code execute if there is duplicate values in an array.
count++;
// Inserting the index one by one.
arr.push(originalArray.indexOf(elem, count))
}
});
// Result array.
document.write("Original Array<br/>"+originalArray+" : Original Array");
document.write("<br/><br/>");
document.write("Original Index<br/>"+arr+" : Orignal Index");
document.write("<br/><br/>");
document.write("Deep Copy<br/>"+deepCopy+" : Sorted Array");
document.write("<br/><br/>");
// Index[0] = Original Array [2];
for(n=0; n<arr.length; n++){
a2 = originalArray.indexOf(deepCopy[n]);
document.write(n+"] "+originalArray[a2]+" - Original Index: "+a2+"<br/>");
};
document.write("<br/>For the Number 8 at position 1,2,3- The indexes shold read 1,3 & 6 instead of three consecutive 1's");The problem I have is where there are duplicate numbers - in this case the number eight appears three times but when sorted it only return the index of the first incidence of the number - instead of displaying the indexes 1,3,6.
To elaborate @epascarello comment, you can map the copied array to include the index for each element before sorting. no need to separate indexes into a separate array.
// Original array.
const originalArray = [3, 8, 2, 8, 6, 9, 8, 4];
// Creating a deep copy of an original array.
const deepCopy = [...originalArray].map((e, i) => [e, i]).sort(function(a, b){
return b[0]-a[0]
});
// Result array.
document.write("Original Array<br/>"+originalArray+" : Original Array");
document.write("<br/><br/>");
document.write("Deep Copy<br/>"+deepCopy+" : Sorted Array");
document.write("<br/><br/>");
let n = 0
for(let [e, i] of deepCopy){
n++
document.write(n+"] "+ e +" - Original Index: "+ i +"<br/>");
};