ParseInt() method on array

Question

I am wondering to how to get number from an array. I have tried its give me NaN error

<script type="text/javascript">

$(function(){

var Arr = [ 'h78em', 'w145px', 'w13px' ]

alert(parseInt(Arr[0]))


})
</script>

If you just want all the digits in the string you could use a regex: `parseInt(Arr[0].replace(/\D/g), '')`. Do you care about more complex cases like `abc123def456`? — verdesmarald, Aug 30 '12 at 08:10

Fabrizio Calderan · Answer 1 · 2012-08-30T08:12:21.300

3

try with

+Arr[0].replace(/\D/g, '');

Example fiddle: http://jsfiddle.net/t6yCV/

Starting + is working like parseInt() and it is necessary if you need to perform some mathematical operation with the number obtained: in fact

typeof Arr[0].replace(/\D/g,'')  // String
typeof +Arr[0].replace(/\D/g,'') // Number

edited Aug 30 '12 at 08:12

answered Aug 30 '12 at 08:06

Fabrizio Calderan

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score 3 · Answer 2 · edited May 23 '17 at 12:27

3

Try:

['h78em', 'w145px', 'w13px']
 .map(function(a){return ~~(a.replace(/\D/g,''));});
 //=> [78, 145, 13]

See also

Or use a somewhat more elaborate String prototype extension:

String.prototype.intsFromString = function(combine){
 var nums = this.match(/\d{1,}/g);
 return !nums ? 0 
         : nums.length>1 ? combine ? ~~nums.join('') 
           : nums.map(function(a){return ~~a;}) 
         : ~~nums[0];
};
// usage
'abc23'.intsFromString();          //=> 23
'3abc121cde'.intsFromString();     //=> [3,121]
'3abc121cde'.intsFromString(true); //=> 3121
'abcde'.intsFromString();          //=> 0
// and ofcourse
['h78em', 'w145px', 'w13px'].map(function(a){return a.intsFromString();});
//=> [78, 145, 13]

edited May 23 '17 at 12:27

Community

1
1

answered Aug 30 '12 at 08:21

KooiInc

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Nice: just for simplification: `[^\d] ==> \D` - and unfortunately IE8 doesn't support `map` – Fabrizio Calderan Aug 30 '12 at 08:35
@Fabrizio: yep, adjusted. You can find a `Array.prototype.map` shim @ https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Array/map – KooiInc Aug 30 '12 at 08:56

score 1 · Accepted Answer · answered Aug 30 '12 at 08:06

1

You can build a function that builds the number from your string:

function stringToNum(str){
  num = 0;
  for (i = 0; i < str.length; i++) 
    if (str[i] >= '0' && str[i] <= '9') 
      num = num * 10 + parseInt(str[i]);
  return num;
}

jsFiddle : http://jsfiddle.net/8WwHh/

answered Aug 30 '12 at 08:06

gabitzish

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Wow!, Can you please tell what is the logic behind it – Jitender Aug 30 '12 at 08:10
1

you start with num = 0, and iterate the characters from the string. If you find a digit, you multiply your number with 10 and add the new digit at the end. – gabitzish Aug 30 '12 at 08:11
What to do with `stringToNum('123abc345def')`? – KooiInc Aug 30 '12 at 08:58
It depends: would you like to see the values as separate numbers, or as a single number? The latter case is what your method covers, but for the first case your method wouldn't be sufficient. – KooiInc Aug 30 '12 at 09:14

score 1 · Answer 4 · answered Aug 30 '12 at 11:23

1

Try this:

var Arr = [ 'h78em', 'w145px', 'w13px' ]

function stringToNum(str){
  return str.match(/\d+/g);

}

alert(stringToNum(Arr[0]));

http://jsfiddle.net/8WwHh/1/

answered Aug 30 '12 at 11:23

Dhanasekar Murugesan

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Snake Eyes · Answer 5 · 2012-08-30T08:12:33.313

0

How about

alert(parseInt(Arr[0].replace(/[a-z_A-Z]/g,"")));

jsfiddle

edited Aug 30 '12 at 08:12

answered Aug 30 '12 at 08:06

Snake Eyes

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Mind for case sensitiveness. Also, this would make something like "a52eb2" in 522. Not sure if that is correct, you might end up with a different number. – Flater Aug 30 '12 at 08:09

score 0 · Answer 6 · answered Aug 30 '12 at 08:09

0

Yet another quick and dirty solution:

alert(Arr[0].match("\\d+"));

answered Aug 30 '12 at 08:09

MAK

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score 0 · Answer 7 · answered Aug 30 '12 at 09:02

0

Try it,this regex is better

parseInt('h343px'.replace(/^[a-zA-Z]+/,''),10)

answered Aug 30 '12 at 09:02

yao lu

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Try `parseInt('{h343px}'.replace(/^[a-zA-Z]+/,''),10)`? – KooiInc Aug 30 '12 at 09:12

ParseInt() method on array

7 Answers7