I have many lists that need to be sorted according to specified interest. Alphabetical and numerical sorts using the array of values will not work.
For an example. The below cities, need to appear in this order. How can I accomplish this using JavaScript? Is there a way, I can represent each city with a numerical value then use the numerical values to sort the cities to the desired order below?
Salisbury, High Point, Wake, Charlotte, Raleigh, Cary, Wilson
Put the keys into a map:
var cityScores = {
Salisbury: 5, High Point: 10, Wake: 15, Charlotte: 20, Raleigh: 25, Cary: 30, Wilson: 35
};
Then when you sort you can just refer to the scorings in that object:
cityList.sort(function(city1, city2) {
return cityScores[city1] - cityScores[city2];
});
If the array is an array of objects with the city in it, then:
objectList.sort(function(o1, o2) {
return cityScores[o1.city] - cityScores[o2.city];
});
A solution for more than only the listed words, with precedence of the listed words.
var data = [
'Salisbury', 'Charlotte', 'Frankfurt', 'Düsseldorf', 'Raleigh',
'Cary', 'Wilson', 'High Point', 'Wake', 'New Jersey'
],
customSort = [
'Salisbury', 'High Point', 'Wake', 'Charlotte', 'Raleigh',
'Cary', 'Wilson'
],
customLookup = customSort.reduce(function (r, a, i) {
r[a] = ('000'+i).slice(-4); return r;
}, {}),
customSortFn = function (a, b) {
return (customLookup[a] || a).localeCompare(customLookup[b] || b);
};
document.write('<pre>' + JSON.stringify(data.sort(customSortFn), 0, 4) + '</pre>');
Array.prototype.sort() can use a compareFunction to sort elements:
var arr = [];
arr.sort(compare);
/** copy paste from mdn - create whatever logic to sort by **/
function compare(a, b) {
if (a is less than b by some ordering criterion) {
return -1;
}
if (a is greater than b by the ordering criterion) {
return 1;
}
// a must be equal to b
return 0;
}
A simplified version of Nina Scholz's solution, putting the unrecognized elements at the end, without changing their order relative to each other. To avoid dealing with localeCompare.
var data = [
'Salisbury', 'Charlotte', 'Frankfurt', 'Düsseldorf', 'Raleigh',
'Cary', 'Wilson', 'High Point', 'Wake', 'New Jersey'
];
var priority = {
'Salisbury': 10, 'High Point': 20, 'Wake': 30, 'Charlotte': 40,
'Raleigh': 50, 'Cary': 60, 'Wilson': 70, // 'OTHER': 9999
};
data.sort( function (a, b) {
return (priority[a] || 9999) - (priority[b] || 9999);
});
