String[]

{⍵⊂⍨⍵∊∊⍕¨⍳10}

{⍵⊂⍨⍵∊∊⍕¨⍳10}

{⍵⊂⍨⍵∊∊⍕¨⍳10}

{        ⍳10}  make an array of naturals from 1 to 10
       ⍕¨      convert each number into a string
      ∊        concatenate the strings into one (it doesn't matter that there are two 1s)
    ⍵∊         test which chars from the argument are contained in the digit string
 ⍵⊂⍨           use it to perform a partitioned enclose, which splits the string as needed

{⍵⊂⍨⍵∊∊⍕¨⍳10} 'ab5c0x'
 5  0
      {⍵⊂⍨⍵∊∊⍕¨⍳10}  'z526ks4f.;8]p'
 526  4  8

{q,⍵,q←'"'}¨ {⍵⊂⍨⍵∊∊⍕¨⍳10} 'ab5c0x'
 "5"  "0"
      {q,⍵,q←'"'}¨ {⍵⊂⍨⍵∊∊⍕¨⍳10}  'z526ks4f.;8]p'
 "526"  "4"  "8"

f()(echo ${1//+([!0-9])/ })

$ a=($(f "ab5c0x")); echo ${a[@]}
5 0
$ a=($(f "z526ks4f.;8]p")); echo ${a[@]}
526 4 8
$

>>> sample=["abc123def456","aitew034snk582:3c","as5493tax54\430-52@g9.fc","sasprs]tore"re\forz"]
>>> [f(data) for data in sample]
[['123', '456'], ['034', '582', '3'], ['5493', '54', '430', '52', '9'], []]

function split() {
tr -c 0-9  <<E
$1
E
}

$ for N in $(split 'abc123def456'); do echo $N; done
123
456

function split() (tr -c 0-9  <<<$1)

a=(`split "abc123def456"`); echo ${a[@]}

StringCases[#,DigitCharacter..]&

inps ={"abc123def456", "aitew034snk582:3c", "as5493tax54\430-52@g9.fc",
        "sasprs]tore"re\forz"}
StringCases[#,DigitCharacter..]&/@inps

{{"123", "456"},
 {"034", "582", "3"},
 {"5493", "54", "430", "52", "9"},
 {}
}

StringCases[#, RegularExpression["[0-9]+"]] &

f := [:s|s asCollectionOfSubCollectionsSeparatedByAnyForWhich:[:ch|ch isDigit not]]

[ 123 456 ]
[ 034 582 3 ]
[ 5493 54 430 52 9 ]
[ ]

Function f(i)
For x=1 To Len(i)
c=Mid(i,x,1)
If Not IsNumeric(c) Then
Mid(i,x,1)=" "
End If
Next
Do
l=Len(i)
i=Replace(i,"  "," ")
l=l-Len(i)
Loop Until l=0
f=Split(Trim(i)," ")
End Function

Input: "ab5c0x"
Output: 5,0

Input: "z526ks4f.;8]p"
Output: 526,4,8

function f(a){
 a+=".",b="",c=[];for(i in a)b=+a[i]+1?b+a[i]:b?(c.push(b),""):b;return c
}

a+=".",b="",c=[];        //add '.' to input so we dont have to check if it ends in a digit
for(i in a)
    b=+a[i]+1?           //check if digit, add to string if it is
        b+a[i]:
    b?                   //if it wasnt a digit and b contains digits push it
        (c.push(b),""):  //into the array c and clear b
    b;                   //else give me b back
return c

console.log(f("abc123def456"));
console.log(f("aitew034snk582:3c"));
console.log(f("as5493tax54\430-52@g9.fc"));
console.log(f("sasprs]tore"re\forz"));

["123", "456"]
["034", "582", "3"]
["5493", "54", "430", "52", "9"]
[]

f=function(x){
s=strsplit(x,"",T)[[1]]
i=s%in%0:9
split(s,c(0,cumsum(!!diff(i))))[c(i[1],!i[1])]
}

> f("abc123def456")
$`1`
[1] "1" "2" "3"

$`3`
[1] "4" "5" "6"

> f("aitew034snk582:3c")
$`1`
[1] "0" "3" "4"

$`3`
[1] "5" "8" "2"

$`5`
[1] "3"

> f("as5493tax54\430-52@g9.fc")
$`1`
[1] "5" "4" "9" "3"

$`3`
[1] "5" "4"

$`5`
[1] "4" "3" "0"

$`7`
[1] "5" "2"

$`9`
[1] "9"

> f("sasprs]tore"re\forz")
$<NA>
NULL

function f($a){
$i=0;while($i<strlen($a)){!is_numeric($a[$i])&&$a[$i]='-';$i++;}return array_filter(explode('-',$a),function($v){return!empty($v);});
}

static string[] SplitAtNonDigits(string s)
{
    return new string(s.Select(c=>47<c&c<58?c:',').ToArray()).Split(new[]{','},(StringSplitOptions)1);
}

function n(s){
var r=[];s.split('').reduce(function(p,c){if(!isNaN(parseInt(c))){if(p)r.push([]);r[r.length-1].push(c);return 0;}return 1;},1);return r;
}

function n(s) {
  var r = [];
  s.split('').reduce(function (p, c) {
    if (!isNaN(parseInt(c))) {
      if (p) {
        r.push([]);
      }
      r[r.length - 1].push(c);
      return 0;
    }
    return 1;
  }, 1);
  return r;
}

f=->s{s.tr("
-/:-~",' ').split}

def find_digits(_input_):
    a,b = [], ""
    for i in list(_input_):
        if i.isdigit(): b += i
        else:
            if b != "": a.append(b)
            b = ""
    if b != "": a.append(b)
    return a

def f(s, o=[], c=""):
    for i in s:
        try:int(i);c+=i
        except:o+=[c];c=""
    return [i for i in o+[c] if i]

assert f("abc123def456") == ["123", "456"]
assert f("aitew034snk582:3c") == ["034", "582", "3"]
assert f("as5493tax54\430-52@g9.fc") == ["5493", "54", "430", "52", "9"]
assert f("sasprs]tore"re\forz") == []

function f($x) {
// Only the following line counts:
for($h=$i=0;sscanf(substr("a$x",$h+=$i),"%[^0-9]%[0-9]%n",$j,$s,$i)>1;)$a[]=$s;return@$a;
}

php > echo json_encode(f("abc123def456")), "n";
["123","456"]
php > echo json_encode(f("aitew034snk582:3c")), "n";
["034","582","3"]
php > echo json_encode(f("as5493tax54\430-52@g9.fc")), "n";
["5493","54","430","52","9"]
php > echo json_encode(f("sasprs]tore"re\forz")), "n";
null

{-# LANGUAGE OverloadedStrings #-}
import Data.Char (isDigit)
import Data.Text (split)

f=filter(/="").split(not.isDigit)

(defun extract-numeric-substrings (string &aux (start 0) (end 0) (result (make-array 0 :adjustable t :fill-pointer 0)))
  (loop
     (unless (and end (setq start (position-if #'digit-char-p string :start end)))
       (return result))
     (setq end (position-if (complement #'digit-char-p) string :start (1+ start)))
     (vector-push-extend (subseq string start end) result)))

(extract-numeric-substrings "abc123def456")
#("123" "456")

(extract-numeric-substrings "aitew034snk582:3c")
#("034" "582" "3")

(extract-numeric-substrings "as5493tax54\430-52@g9.fc")
#("5493" "54" "430" "52" "9")

(extract-numeric-substrings "sasprs]tore"re\forz")
#()

(defun extract-numeric-substrings (string
                                   &aux (start 0) (end 0)
                                   (result (make-array 0 :adjustable t :fill-pointer 0))
                                   (x (loop
                                         (unless (and end (setq start (position-if #'digit-char-p string :start end)))
                                           (return result))
                                         (setq end (position-if (complement #'digit-char-p) string :start (1+ start)))
                                         (vector-push-extend (subseq string start end) result))))
  x)

(LOOP(UNLESS(AND END(SETQ START(POSITION-IF #'DIGIT-CHAR-P STRING :START END)))(RETURN RESULT))(SETQ END(POSITION-IF(COMPLEMENT #'DIGIT-CHAR-P)STRING :START(1+ START)))(VECTOR-PUSH-EXTEND(SUBSEQ STRING START END)RESULT))

(defun extract-numeric-substrings (s &aux (b 0) (e 0) (r (make-array 0 :fill-pointer 0)))
  (loop
     with d = #'digit-char-p
     while (and e (setq b (position-if d s :start e)))
     finally (return r)
     do
       (setq e (position-if-not d s :start (1+ b)))
       (vector-push-extend (subseq s b e) r)))

(LOOP WITH D = #'DIGIT-CHAR-P WHILE(AND E(SETQ B(POSITION-IF D S :START E)))FINALLY(RETURN R)DO(SETQ E(POSITION-IF-NOT D S :START(1+ B)))(VECTOR-PUSH-EXTEND(SUBSEQ S B E)R))

Function t(s)
Dim o()
For Each c In Split(StrConv(s,64),Chr(0))
d=IsNumeric(c)
If b And d Then
n=n&c
ElseIf d Then:ReDim Preserve o(l):b=1:n=c
ElseIf b Then:b=0:o(l)=n:l=l+1:End If:Next:t=o
End Function

remove-each n s: split s complement charset"0123456789"[empty? n]s

f: func [s] [
    remove-each n s: split s complement charset "0123456789" [empty? n]
    s
]

>> f "abc123def456"
== ["123" "456"]

>> f "aitew035snk582:3c"
== ["035" "582" "3"]

>> f "as5493tax54\430-52@g9.fc"
== ["5493" "54" "430" "52" "9"]

>> f {sasprs]torer"re\forz}
== []

function nums(s) {
s+=l='length';r=[''];for(k=i=0;c=s[i];i++)r[k]+=+c+1?c:r[k+=!!r[k][l]]='';
r[l]--;return r
}

function nums(s) {
    var i, e, r, c, k;
    k = 0;
    s+='x'; // ensure the input does not end with a digit
    r=[''];
    for (i=0;i<s.length;i++) {
        c=s[i];
        if (+c+1) { // if the current character is a digit, append it to the last entry
            r[k] += c;
        }
        else { // otherwise, add a new entry if the last entry is not blank
            k+=!!r[k].length;
            r[k] = '';
        }
    }
    r.length--; // strip the last entry, known to be blank
    return r;
}

x
## [1] "wNEKbS0q7hAXRVCF6I4S" "DpqW50YfaDMURB8micYd" "gwSuYstMGi8H7gDAoHJu"
require(stringi)
stri_split_charclass(x,"\P{N}",o=T)
## [[1]]
## [1] "0" "7" "6" "4"

## [[2]]
## [1] "50" "8"

## [[3]]
## [1] "8" "7"

<?php

$a = function($s) {
foreach(str_split($s)as$c)$b[]=is_numeric($c)?$c:".";return array_filter(explode('.',implode($b)));
};

var_dump($a("abc123def456"));
var_dump($a("aitew034snk582:3c"));
var_dump($a("as5493tax54\430-52@g9.fc"));
var_dump($a("sasprs]tore"re\forz"));

array(2) {
  [3]=>
  string(3) "123"
  [6]=>
  string(3) "456"
}
array(3) {
  [5]=>
  string(3) "034"
  [8]=>
  string(3) "582"
  [9]=>
  string(1) "3"
}
array(5) {
  [2]=>
  string(4) "5493"
  [5]=>
  string(2) "54"
  [6]=>
  string(3) "430"
  [7]=>
  string(2) "52"
  [9]=>
  string(1) "9"
}
array(0) {
}

function n(x){
y=[],i=0,z=t=''
while(z=x[i++])t=!isNaN(z)?t+z:t&&y.push(t)?'':t
if(t)y.push(t)
return y
}