Fast way to get the min max values among properties of object

Question

I have an object in javascript like this      a  4   b  0 5    c  0 35   d  5     Is there a fast way to get the minimum and maximum value among the properties without having to loop through them all  because the object I have is huge and I need to get the min max value every two seconds   The values of the object keeps changing

User · Accepted Answer

There s no way to find the maximum   minimum in the general case without looping through all the n elements  if you go from  1 to n-1  how do you know whether the element n isn t larger  or smaller  than the current max min   You mentioned that the values change every couple of seconds  If you know exactly which values change  you can start with your previous max min values  and only compare with the new ones  but even in this case  if one of the values which were modified was your old max min  you may need to loop through them again  Another alternative - again  only if the number of values which change are small - would be to store the values in a structure such as a tree or a heap  and as the new values arrive you d insert  or update  them appropriately  But whether you can do that is not clear based on your question  If you want to get the maximum   minimum element of a given list while looping through all elements  then you can use something like the snippet below  but you will not be able to do that without going through all of them var list      quot a quot  4   quot b quot  0 5    quot c quot  0 35   quot d quot  5    var keys   Object keys list   var min   list keys 0       ignoring case of empty list for conciseness var max   list keys 0    var i   for  i   1  i  lt  keys length  i          var value   list keys i        if  value  lt  min  min   value      if  value  gt  max  max   value

User · Answer

You can also try with Object values   x000D   x000D  const points     Neel  100  Veer  89  Shubham  78  Vikash  67    x000D   x000D  const vals   Object values points   x000D  const max   Math max    vals   x000D  const min   Math min    vals   x000D  console log max   x000D  console log min   x000D   x000D   x000D

User · Answer

min and max have to loop through the input array anyway - how else would they find the biggest or smallest element   So just a quick for  in loop will work just fine   var min   Infinity  max   -Infinity  x  for  x in input        if  input x   lt  min  min   input x       if  input x   gt  max  max   input x

User · Answer

Here s a solution that allows you to return the key as well and only does one loop  It sorts the Object s entries  by val  and then returns the first and last one   Additionally  it returns the sorted Object which can replace the existing Object so that future sorts will be faster because it will already be semi-sorted   better than O n   It s important to note that Objects retain their order in ES6    x000D   x000D  const maxMinVal    obj    gt    x000D    const sortedEntriesByVal   Object entries obj  sort     v1      v2     gt  v1 - v2   x000D   x000D    return   x000D      min  sortedEntriesByVal 0   x000D      max  sortedEntriesByVal sortedEntriesByVal length - 1   x000D      sortedObjByVal  sortedEntriesByVal reduce  r   k  v     gt        r   k   v          x000D       x000D     x000D   x000D  const obj     x000D    a  4  b  0 5  c  0 35  d  5 x000D     x000D   x000D  console log maxMinVal obj    x000D   x000D   x000D

User · Answer

1  iterate through object values and get them    2  sort that array of values ascending or descending and take first         which is min or max accordingly let obj      a   4   b   0 5   c   0 35   d   5   let min   Object values obj  sort  prev  next    gt  prev - next  0     0 35 let max   Object values obj  sort  prev  next    gt  next - prev  0     5

User · Answer

Update  Modern version  ES6    x000D   x000D  let obj     a  4  b  0 5   c  0 35  d  5     let arr   Object values obj   let min   Math min    arr   let max   Math max    arr    console log   Min value    min   max value    max      x000D   x000D   x000D    Original Answer  Try this  let obj     a  4  b  0 5   c  0 35  d  5    var arr   Object keys  obj   map function   key     return obj key        and then  var min   Math min apply  null  arr    var max   Math max apply  null  arr     Live demo  http   jsfiddle net 7GCu7 1

User · Answer

You could try   const obj     a  4  b  0 5   c  0 35  d  5    const max   Math max apply null  Object values obj    console log max     5

User · Answer

For nested structures of different depth  i e   node   leaf  4   leaf  1   this will work  using lodash or underscore    function getMaxValue d       if typeof d      number             return d        else if typeof d      object             return   max   map   keys d   function key                return getMaxValue d key                       else           return false

User · Answer

var newObj     a  4  b  0 5   c  0 35  d  5    var maxValue   Math max    Object values newObj   var minValue   Math min    Object values newObj

User · Answer

Sorted let Sorted   Object entries    quot a quot  4   quot b quot  0 5    quot c quot  0 35   quot d quot  5    sort  prev  next    gt  prev 1  - next 1    gt  gt       c   0 35       b   0 5       a   4       d   5         Min  Sorted shift    gt  gt     c   0 35       Max  Sorted pop    gt  gt     d   5

User · Answer

This works for me   var object     a  4  b  0 5   c  0 35  d  5       Take all value from the object into list var valueList     map object function v        return v      var max   valueList reduce function a  b    return Math max a  b       var min   valueList reduce function a  b    return Math min a  b

User · Answer

Using the lodash library you can write shorter       a  4   b  0 5    c  0 35   d  5    values   max

[javascript] Fast way to get the min/max values among properties of object

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