Sort list in descending alphabetical order

user_14337954 0
Viewed 90

I have a list of Tasks and each task contains the property 'fromPriority'. This property is a string and its values can only be 'HIGH', 'AVERAGE', 'LOW' or a numeric string. I need to order this list by this property, but I need that the numeric strings are ordered first in desceding order. For example, if I have the following values:

['1', '99', '10', 'HIGH', '5', 'LOW']

I want the order to be

['99', '10', '5', '1', 'HIGH', 'LOW']
javascript
3 Answers

This may be one possible solution to achieve the desired objective.

Code Snippet

const myDict = { // helper object to assign numeric values for High, Average, Low
'HIGH': 2, 'AVERAGE': 1, 'LOW': 0
};

const customSort = arr => (
  [...arr].sort((a, b) => (     // shallow-copy 'arr' and use '.sort()' 
    a in myDict && b in myDict  // if both a & b are High, Average or Low 
    ? myDict[b] - myDict[a]     // find difference in their costs (using 'myDict') 
    : b in myDict               // else, if b is either High, Average or Low
      ? -1                      // then, keep b below a
      : a in myDict             // else, if a is either High, Average or Low
        ? 1                     // then, keep a below b
        : +b - +a               // else, if both a & b are numeric-strings
  ))                            // convert to number (using '+') and order based on difference
);

const rawData = ['1', '99', '10', 'HIGH', '5', 'LOW'];

console.log(`[${rawData.join(', ')}]`, customSort(rawData));

console.log(
  "['15', 'AVERAGE', '20', 'HIGH', '52', 'LOW']",
  customSort(['15', 'AVERAGE', '20', 'HIGH', '52', 'LOW'])
);
console.log(
  "['31', '49', '17', 'AVERAGE', '25', 'LOW']",
  customSort(['31', '49', '17', 'AVERAGE', '25', 'LOW'])
);
console.log(
  "['41', 'HIGH', '90', 'LOW', '45', 'AVERAGE']",
  customSort(['41', 'HIGH', '90', 'LOW', '45', 'AVERAGE'])
);
console.log(
  "['71', '32', '05', 'HIGH', '75', 'LOW']",
  customSort(['71', '32', '05', 'HIGH', '75', 'LOW'])
);

Explanation

Inline comments in the above code-snippet provide relevant description of the steps.

user_136588160

This code implements a custom sort function to sort for the condition you have returning 1/-1 means a is greater/smaller than b respectively. 

let arr = ['99', '100', '2']
const custom_sort = (a, b) => {
  const numericA = !isNaN(a);
  const numericB = !isNaN(b);
  if (numericA && !numericB) return -1;
  if (!numericA && numericB) return 1;
  if (numericA && numericB) {
    if (parseInt(a) > parseInt(b)) return -1;
    return 1;
  } else {
    if(a==='LOW')return 1;
    if(a==='MED'&&b==='HIGH')return 1;
    return -1;
  }
}
console.log(arr.sort(custom_sort));

user_71488510

Here is a simple solution

function customSort(arr) {
    //first sort only the numbers
    let newArr = arr
        .filter(el => !isNaN(el)) //filter numbers
        .sort((a, b) => parseInt(b) - parseInt(a)) //sort numbers
    //now the alplabical part
    let str = ['HIGH', 'AVERAGE', 'LOW'] //arrange all possible strings
    str.forEach(el => (arr.includes(el) ? newArr.push(el) : null)) //push matched items in the newArr
    return newArr
}
let input = ['1', '99', '10', 'HIGH', '5', 'LOW']
let output = customSort(input)
console.log(output)

user_143105510
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