How to sort strings in JavaScript

Question

I have a list of objects I wish to sort based on a field attr of type string  I tried using -  list sort function  a  b        return a attr - b attr      but found that - doesn t appear to work with strings in JavaScript  How can I sort a list of objects based on an attribute with type string

User · Accepted Answer

Use String prototype localeCompare a per your example   list sort function  a  b        return       a attr  localeCompare b attr        We force a attr to be a string to avoid exceptions  localeCompare has been supported since Internet Explorer 6 and Firefox 1  You may also see the following code used that doesn t respect a locale   if  item1 attr  lt  item2 attr    return -1  if   item1 attr  gt  item2 attr    return 1  return 0

User · Answer

In your operation in your initial question  you are performing the following operation   item1 attr - item2 attr   So  assuming those are numbers  i e  item1 attr    1   item2 attr    2   You still may use the       operator  or other strict evaluators  provided that you ensure type  The following should work   return parseInt item1 attr  - parseInt item2 attr     If they are alphaNumeric  then do use localCompare

User · Answer

You should use   or  lt  and    here  So the solution would be   list sort function item1  item2        var val1   item1 attr          val2   item2 attr      if  val1    val2  return 0      if  val1  gt  val2  return 1      if  val1  lt  val2  return -1

User · Answer

An updated answer  October 2014   I was really annoyed about this string natural sorting order so I took quite some time to investigate this issue  I hope this helps   Long story short  localeCompare   character support is badass  just use it  As pointed out by Shog9  the answer to your question is   return item1 attr localeCompare item2 attr     Bugs found in all the custom javascript  natural string sort order  implementations  There are quite a bunch of custom implementations out there  trying to do string comparison more precisely called  natural string sort order   When  playing  with these implementations  I always noticed some strange  natural sorting order  choice  or rather mistakes  or omissions in the best cases    Typically  special characters  space  dash  ampersand  brackets  and so on  are not processed correctly   You will then find them appearing mixed up in different places  typically that could be    some will be between the uppercase  Z  and the lowercase  a   some will be between the  9  and the uppercase  A  some will be after lowercase  z    When one would have expected special characters to all be  grouped  together in one place  except for the space special character maybe  which would always be the first character   That is  either all before numbers  or all between numbers and letters  lowercase  amp  uppercase being  together  one after another   or all after letters   My conclusion is that they all fail to provide a consistent order when I start adding barely unusual characters  ie  characters with diacritics or charcters such as dash  exclamation mark and so on    Research on the custom implementations    Natural Compare Lite https   github com litejs natural-compare-lite   Fails at sorting consistently https   github com litejs natural-compare-lite issues 1 and http   jsbin com bevututodavi 1 edit js console   basic latin characters sorting http   jsbin com bevututodavi 5 edit js console  Natural Sort https   github com javve natural-sort   Fails at sorting consistently  see issue https   github com javve natural-sort issues 7 and see basic latin characters sorting http   jsbin com cipimosedoqe 3 edit js console  Javascript Natural Sort https   github com overset javascript-natural-sort   seems rather neglected since February 2012  Fails at sorting consistently  see issue https   github com overset javascript-natural-sort issues 16 Alphanum http   www davekoelle com files alphanum js   Fails at sorting consistently  see http   jsbin com tuminoxifuyo 1 edit js console   Browsers  native  natural string sort order  implementations via localeCompare    localeCompare   oldest implementation  without the locales and options arguments  is supported by IE6   see http   msdn microsoft com en-us library ie s4esdbwz v vs 94  aspx  scroll down to localeCompare   method   The built-in localeCompare   method does a much better job at sorting  even international  amp  special characters  The only problem using the localeCompare   method is that  the locale and sort order used are entirely implementation dependent   In other words  when using localeCompare such as stringOne localeCompare stringTwo   Firefox  Safari  Chrome  amp  IE have a different sort order for Strings   Research on the browser-native implementations    http   jsbin com beboroyifomu 1 edit js console - basic latin characters comparison with localeCompare   http   jsbin com viyucavudela 2  - basic latin characters comparison with localeCompare   for testing on IE8 http   jsbin com beboroyifomu 2 edit js console - basic latin characters in string comparison   consistency check in string vs when a character is alone https   developer mozilla org en-US docs Web JavaScript Reference Global Objects String localeCompare - IE11  supports the new locales  amp  options arguments   Difficulty of  string natural sorting order   Implementing a solid algorithm  meaning  consistent but also covering a wide range of characters  is a very tough task  UTF8 contains more than 2000 characters  amp  covers more than 120 scripts  languages    Finally  there are some specification for this tasks  it is called the  Unicode Collation Algorithm   which can be found at http   www unicode org reports tr10    You can find more information about this on this question I posted https   softwareengineering stackexchange com questions 257286 is-there-any-language-agnostic-specification-for-string-natural-sorting-order  Final conclusion  So considering the current level of support provided by the javascript custom implementations I came across  we will probably never see anything getting any close to supporting all this characters  amp  scripts  languages   Hence I would rather use the browsers  native localeCompare   method  Yes  it does have the downside of beeing non-consistent across browsers but basic testing shows it covers a much wider range of characters  allowing solid  amp  meaningful sort orders   So as pointed out by Shog9  the answer to your question is   return item1 attr localeCompare item2 attr     Further reading    https   softwareengineering stackexchange com questions 257286 is-there-any-language-agnostic-specification-for-string-natural-sorting-order How do you do string comparison in JavaScript  Javascript   natural sort of alphanumerical strings Sort Array of numeric  amp  alphabetical elements  Natural Sort  Sort mixed alpha numeric array https   web archive org web 20130929122019 http   my opera com GreyWyvern blog show dml 1671288 https   web archive org web 20131005224909 http   www davekoelle com alphanum html http   snipplr com view 36012 javascript-natural-sort  http   blog codinghorror com sorting-for-humans-natural-sort-order    Thanks to Shog9 s nice answer  which put me in the  right  direction I believe

User · Answer

var str     v   a   da   c   k   l   var b   str join     split     sort   reverse   join     console log b

User · Answer

Use sort   straight forward without any - or  lt   x000D   x000D  const areas     hill    beach    desert    mountain   console log areas sort        To print in descending way console log areas sort   reverse    x000D   x000D   x000D

User · Answer

list sort function item1  item2       return   item1 attr  gt  item2 attr       item1 attr     item2 attr  - 1        How they work samples      aaa  gt  bbb       aaa     bbb  -1   false     false -1 0  0-1 -1     bbb  gt  aaa       bbb     aaa  -1   true     false -1 1  0-1 1     aaa  gt  aaa       aaa     aaa  -1   false     true -1 0  1-1 0

User · Answer

since strings can be compared directly in javascript  this will do the job  list sort function  a  b        return a attr  gt  b attr   1  -1       the subtraction in a sort function is used only when non alphabetical  numerical  sort is desired and of course it does not work with strings

User · Answer

I had been bothered about this for long  so I finally researched this and give you this long winded reason for why things are the way they are   From the spec   Section 11 9 4   The Strict Equals Operator          The production EqualityExpression   EqualityExpression     RelationalExpression is evaluated as follows   - Let lref be the result of evaluating EqualityExpression  - Let lval be GetValue lref   - Let rref be the result of evaluating RelationalExpression  - Let rval be GetValue rref   - Return the result of performing the strict equality comparison    rval     lval   See 11 9 6    So now we go to 11 9 6  11 9 6   The Strict Equality Comparison Algorithm  The comparison x     y  where x and y are values  produces true or false   Such a comparison is performed as follows   - If Type x  is different from Type y   return false  - If Type x  is Undefined  return true  - If Type x  is Null  return true  - If Type x  is Number  then     - If Type x  is String  then return true if x and y are exactly the    same sequence of characters  same length and same characters in    corresponding positions   otherwise  return false    That s it  The triple equals operator applied to strings returns true iff the arguments are  exactly the same strings  same length and same characters in corresponding positions    So     will work in the cases when we re trying to compare strings which might have arrived from different sources  but which we know will eventually have the same values - a common enough scenario for inline strings in our code  For example  if we have a variable named connection state  and we wish to know which one of the following states   connecting    connected    disconnecting    disconnected   is it in right now  we can directly use the        But there s more  Just above 11 9 4  there is a short note   NOTE 4        Comparison of Strings uses a simple equality test on sequences of code    unit values  There is no attempt to use the more complex  semantically oriented   definitions of character or string equality and collating order defined in the    Unicode specification  Therefore Strings values that are canonically equal   according to the Unicode standard could test as unequal  In effect this    algorithm assumes that both Strings are already in normalized form    Hmm  What now  Externally obtained strings can  and most likely will  be weird unicodey  and our gentle     won t do them justice  In comes localeCompare to the rescue   15 5 4 9   String prototype localeCompare  that              The actual return values are implementation-defined to permit implementers      to encode additional information in the value  but the function is required      to define a total ordering on all Strings and to return 0 when comparing     Strings that are considered canonically equivalent by the Unicode standard     We can go home now   tl dr   To compare strings in javascript  use localeCompare  if you know that the strings have no non-ASCII components because they are  for example  internal program constants  then     also works

User · Answer

Nested ternary arrow function   a b    gt   a  lt  b   -1   a  gt  b   1   0

User · Answer

Answer  in Modern ECMAScript   list sort  a  b    gt   a attr  gt  b attr  -  a attr  lt  b attr     Or   list sort  a  b    gt    a attr  gt  b attr     - a attr  lt  b attr     Description  Casting a boolean value to a number yields the following    true -  1 false -  0   Consider three possible patterns    x is larger than y   x  gt  y  -  y  lt  x  -  1 - 0 -  1 x is equal to y   x  gt  y  -  y  lt  x  -  0 - 0 -  0 x is smaller than y   x  gt  y  -  y  lt  x  -  0 - 1 -  -1    Alternative    x is larger than y    x  gt  y     - x  lt  y  -  1    0 -  1 x is equal to y    x  gt  y     - x  lt  y  -  0    0 -  0 x is smaller than y    x  gt  y     - x  lt  y  -  0    -1 -  -1   So these logics are equivalent to typical sort comparator functions   if  x    y        return 0    return x  gt  y   1   -1

User · Answer

An explanation of why the approach in the question doesn t work  let products           name   quot laptop quot   price  800          name   quot phone quot   price 200         name   quot tv quot   price  1200     products sort   a  b    gt         let value  a name - b name  console log value   return value        gt  2 NaN  Subtraction between strings returns NaN  Echoing  Alejadro s answer  the right approach is-- products sort   a b    gt  a name  gt  b name   1   -1

User · Answer

lt  doctype html gt   lt html gt   lt body gt   lt p id    myString  gt zyxtspqnmdba lt  p gt   lt p id    orderedString  gt  lt  p gt   lt script gt  var myString   document getElementById  myString   innerHTML  orderString myString   function orderString str        var i   0      var myArray   str split          while  i  lt  str length           var j   i   1          while  j  lt  str length                if  myArray j   lt  myArray i                    var temp   myArray i                   myArray i    myArray j                   myArray j    temp                            j                      i              var newString   myArray join          document getElementById  orderedString   innerHTML   newString     lt  script gt   lt  body gt   lt  html gt

[javascript] How to sort strings in JavaScript

Examples related to javascript

Examples related to string