How to convert all elements in an array to integer in JavaScript

Question

I am getting an array after some manipulation  I need to convert all array values as integers   My sample code  var result string    a b c d 1 2 3 4   result   result string split       alpha   result 0   count   result 1      console log alpha      console log count   count array   count split         count array now contains 1 2 3 4 but I need these value to be in integers   I had used parseInt count array    but it fails  JS considers each value in this array as string

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Using jQuery  you can like the map   method like so      map arr  function val i          return parseInt val

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Just loop the array and convert items   for var i 0  len count array length  i lt len  i         count array i    parseInt count array i   10       Don t forget the second argument for parseInt

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How about this   let x    1 2 3 4 5  let num    x join

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x000D   x000D  var arr     1    2    3    x000D  arr   arr map Number   x000D  console log arr       1  2  3  x000D   x000D   x000D

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const arrString     1   2   3   4   5    const arrInteger   arrString map x   gt  Number parseInt x  10      Above one should be simple enough    One tricky part is when you try to use point free function for map as below  const arrString     1   2   3   4   5    const arrInteger   arrString map Number parseInt     In this case  result will be  1  NaN  NaN  NaN  NaN  since function argument signature for map and parseInt differs     map expects -  value  index  array  where as parseInt expects -    value  radix

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You can do  var arrayOfNumbers   arrayOfStrings map Number      MDN Array prototype map   For older browsers which do not support Array map  you can use Underscore   var arrayOfNumbers     map arrayOfStrings  Number

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var inp readLine     reading the input as one line string var nums inp split      map Number    making an array of numbers console log nums      input   1 9 0 65 5 7  output   1  9  0  65  5  7     what if we dont use  map Number   code   var inp readLine     reading the input as one line string var nums inp split        making an array of strings console log nums     input   1 9 0 65 5 7  output    1    9    0    65    5    7

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The point against parseInt-approach   There s no need to use lambdas and or give radix parameter to parseInt  just use parseFloat or Number instead     Reasons    It s working   var src    1 2 5 4 3   var ids   src split      map parseFloat       1  2  5  4  3   var obj    1       3       4       7        var keys  Object keys obj        1    3    4    7   var ids   keys map parseFloat       1  3  4  7   var arr     1   5   7   11   var ints  arr map parseFloat       1  5  7  11  ints 1       5     false ints 1      5      true ints 2       7     false ints 2      7      true  It s shorter  It s a tiny bit quickier and takes advantage of cache  when parseInt-approach - doesn t        execution time measure function      keep it simple  yeah   gt  var f    function  arr  c  n  m          var i t m s n          for i 0 i   lt c  t arr map m         return n  -s      bind null   2 4 6 8 0 9 7 5 3 1  split       1000000  Date now     gt  f Number     first launch  just warming-up cache  gt  3971    nice      gt  f Number   gt  3964    still the same   gt  f function e  return e    gt  5132    yup  just little bit slower   gt  f function e  return e    gt  5112    second run    and ok    gt  f parseFloat   gt  3727    little bit quicker than  map Number    gt  f parseFloat   gt  3737    all ok   gt  f function e  return parseInt e 10     gt  21852    awww  how adorable      gt  f function e  return parseInt e     gt  22928    maybe  without  10     nope    gt  f function e  return parseInt e     gt  22769    second run    and nothing changes    gt  f Number   gt  3873    and again  gt  f parseFloat   gt  3583    and again  gt  f function e  return e    gt  4967    and again   gt  f function e  return parseInt e 10     gt  21649    dammit  parseInt    gt   lt     Notice  In Firefox parseInt works about 4 times faster  but still slower than others  In total   e  lt  Number  lt  parseFloat  lt  parseInt

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ECMAScript5 provides a map method for Arrays  applying a function to all elements of an array  Here is an example   x000D   x000D  var a     1   2   3   var result   a map function  x       return parseInt x  10         console log result   x000D   x000D   x000D   See Array prototype map

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If you want to convert an Array of digits to a single number just use   Number arrayOfDigits join         Example  const arrayOfDigits    1 2 3 4 5    const singleNumber   Number arrayOfDigits join        console log singleNumber     12345

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You need to loop through and parse convert the elements in your array  like this   var result string    a b c d 1 2 3 4       result   result string split           alpha   result 0       count   result 1       count array   count split       for var i 0  i lt count array length i    count array i     count array i     now count array contains numbers   You can test it out here   If the    is throwing  think of it as   for var i 0  i lt count array length i    count array i    parseInt count array i   10

[javascript] How to convert all elements in an array to integer in JavaScript?

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