Javascript sort() array of mixed data type

Question

If I have an array like:

["23", "765", "sfasf", "2.3E-3", "2.3cE-3"]

How can I order it so numbers(decimals, floats or scientific notation) are ordered ascending and after those strings that aren't numbers(for example "sfasf" or "2.3cE-3")?

Expected order of the example array:

["2.3E-3", "23", "765", "2.3cE-3", "sfasf"]

The order of the strings that can't be converted to numbers doesn't matter, they just must be at the end.

Solution from answer:

 $scope.cleanAndOrder = function(dbo, fieldName) {
    var textareaId = "textarea"+"_"+fieldName ;
    var textarea= document.getElementById(textareaId);

    //(+b && (+a!=a)) : return true (converted to 1) if b is a number and a isn't
    //(a-b) : then compare the numbers if the first comparaison isn't enough
    textarea.value = dbo.attributes[fieldName].sort(function(a,b){ return (+b && !+a) || (a-b) }).join("\n");
    var lines = textarea.value.split("\n");
    textarea.setAttribute('rows', lines.length +2);
 }

Thanks for the comment could you point out a particular function, please? — Al Ex Tsm
– Al Ex Tsm, Commented May 29, 2015 at 11:40

Denys Séguret · Accepted Answer · 2015-05-29 12:08:05Z

5

You can do

var arr = arr.sort(function(a,b){ return ((+b==b) && (+a!=a)) || (a-b) })

The idea is to make two comparisons:

(+b==b) && (+a!=a) : return true (converted to 1) if b is a number and a isn't
a-b : then compare the numbers if the first comparaison isn't enough

More in depth : +a converts a to a number. It is equal (for ==, not for ===) to a when and only when +a is a number (remember, NaN isn't equal to NaN).

edited May 29, 2015 at 12:08

answered May 29, 2015 at 11:40

Denys Séguret

384k90 gold badges813 silver badges779 bronze badges

Sign up to request clarification or add additional context in comments.

10 Comments

user786 Over a year ago

can u please add some explanation for the code u posted?

Al Ex Tsm Over a year ago

Awesome! works like a charm I will accept your answer in a few min. Thanks.

user786 Over a year ago

@DenysSéguret what a-b for?

Denys Séguret Over a year ago

@Alex It's just the difference. If you want to sort numbers you do [3, 32, -4, 21].sort(function(a,b){ return a-b })

Al Ex Tsm Over a year ago

@DenysSéguret Hey thanks again but it swops some values if I run the operation consecutively with the following values: 0.00000000067 asdas 6.14475066 2323.324324 234E12 2.11220065 2.3EE-3 90.96dsfsdf936856 dsfsdf --2.3E-3 38.2046219'

|

Olivier Pirson · Accepted Answer · 2015-05-29 12:06:17Z

0

sort function accept a function comparaison as parameter.

Define your

function compareFct(a, b) {
    if (isNaN(a)) {
        if (isNaN(b)) {  // a and b are strings
            return a.localeCompare(b);
        } else {         // a string and b number
            return 1;  // a > b
        }
    } else {
        if (isNaN(b)) {  // a number and b string
            return -1;  // a < b
        } else {         // a and b are numbers
            return parseFloat(a) - parseFloat(b);
        }
    }
}

and use it like

yourArray.sort(compareFct);

edited May 29, 2015 at 12:06

answered May 29, 2015 at 11:45

Olivier Pirson

8021 gold badge6 silver badges25 bronze badges

Collectives™ on Stack Overflow

Javascript sort() array of mixed data type

2 Answers 2

10 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

10 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related