I have the following array and sort result:
['53-15-9', '53-15-10', '53-15-8'].sort() // => ["53-15-10", "53-15-8", "53-15-9"]
but I need to get the following result:
["53-15-8", "53-15-9", "53-15-10"];
How could I get desired result?
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3Convert them to numbers for the purposes of comparisionMatt Burland– Matt Burland2016-01-19 18:41:58 +00:00Commented Jan 19, 2016 at 18:41
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How to define custom sort function in javascriptvsync– vsync2016-01-19 18:46:31 +00:00Commented Jan 19, 2016 at 18:46
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you should check @Maxali's answer. Doesn't say much, but it's exactly what you need. Also - learn how to provide your own comparison function to sort. Check out the docsAntiokus– Antiokus2016-01-19 18:51:42 +00:00Commented Jan 19, 2016 at 18:51
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6 Answers
To compare numbers instead of strings, first remove '-'. When you use arithmetic
operation, JavaScript first coverts it to numbers.
'53-15-9'.replace(/-/g,'') gives '53159'. You can use closures in sort() to pass compare function that can simply subtract a from b. The following function will sort the array ascending:
['53-15-9', '53-15-10', '53-15-8'].sort(function(a,b){
return a.replace(/-/g,'') - b.replace(/-/g,'')
})Update
As mentioned in the comments, '54-1-1' is less than '53-15-9'. We can change '54-1-1' to '54-01-01'. This only works in double digits. We can do it like:
function customSort(myArray) {
myArray = myArray.map(function(a,b){
var ar = a.split('-');
return ar.map(function(arK, arV){return (arK<10)?'0'+arK : arK.toString();}).join('-');;
})
return myArray.sort(function(a,b){
return a.replace(/-/g,'') - b.replace(/-/g,'')
});
}
customSort(['54-1-2','53-15-9', '53-15-10', '53-15-8']);
// => ["53-15-08", "53-15-09", "53-15-10", "54-01-02"]
5 Comments
vsync
And without regex:
return a.split('-').join('') - b.split('-').join('')
Oriol
But if you add
54-1-1 it will be sorted at the beginning, and probably should be at the end.
Maxali
@Oriol because its converting to numbers. and 5,411 is smaller than 531,519. \
Oriol
@Maxali I know why. I was only noting this may be undesired.
Maxali
@Oriol I updated to achieve this sort. Check the answer.
You can use a custom function for splitting and sorting the parts.
var array = ['53-15-9', '53-15-10', '53-15-8'];
array.sort(function (a, b) {
var aa = a.split('-'),
bb = b.split('-'),
i, r = 0, l = Math.max(aa.length, bb.length);
for (i = 0; !r && i < l; i++) {
r = (aa[i] || 0) - (bb[i] || 0);
}
return r;
});
document.write('<pre>' + JSON.stringify(array, 0, 4) + '</pre>');
Comments
['53-15-9', '53-15-10', '53-15-8'].sort(function(a, b) {
var aNum = parseInt(a.replace(/-/g, ''));
var bNum = parseInt(b.replace(/-/g, ''));
return aNum < bNum ? -1 : aNum > bNum ? 1 : 0;
});
Assuming you want to sort them in numerical order including all the sections, simply remove the -, parse them as an int and then sort the ints in a custom sort function.
Comments
var arr = ['53-15-9', '53-15-10', '53-15-8'];
arr.sort(function(a,b){ return a.replace(/-/g,'') - b.replace(/-/g,'') });
console.log(arr);
output
["53-15-8", "53-15-9", "53-15-10"]
Comments
Try comparing every number separated by - using Array.prototype.every()
var arr = ["53-15-8", "53-15-9", "53-15-10"];
arr.sort(function(a, b) {
var curr = a.split(/-/).map(Number);
var next = b.split(/-/).map(Number);
return curr.every(function(val, key) {return val <= next[key]}) ? a : b
});
console.log(JSON.stringify(arr))
5 Comments
Oriol
['1', '2'] is sorted as ['2', '1']
guest271314
@Oriol Yes, updating currently.
.every() not returning expected results. Approach is to compare each number separated by "-"guest271314
@Oriol See updated post. Adjusted comparison operator to
<= within .every()Oriol
Now
['1-2', '2-1'] is sorted as ['2-1', '1-2'].guest271314
@Oriol See updated post. Substituted returning
a , b for -1, 1You need to define your own custom sorting function. Here is an example:
['53-15-9', '53-15-10', '53-15-8','2', '53-14-4','53-15-99'].sort(function(a,b){ // a and b are elements of the array
// split by - and convert values to number
a = a.split('-').map(function(val){return Number(val)})
b = b.split('-').map(function(val){return Number(val)})
// if one has less elements than another, we consider it should go first
if(a.length != b.length) return a.length > b.length
//else, one goes after another if one of its elements is greater than the others at that index
return a.some(function(val, index){
return val > b[index]
}) == 0 ? -1 : 1
})
//output: ["2", "53-14-4", "53-15-8", "53-15-9", "53-15-10", "53-15-99"]
1 Comment
Oriol
Note you are returning booleans instead of numbers.
false will be treated as 0, which means both values should be considered equal. I can't find any counterexample, but I'm not sure this is completely well-defined. If it isn't, the result of the sort will be implementation-dependent.