How to extract an integer from end of the string in javascript

Question

How can we extract integer (keys) from such a data set ?

data : {
    DAYS7: 234,
    DAYS21: 3456,
    DAYS35: 23456
}

I want to convert this data into two arrays [7, 21, 35] and [234, 3456, 23456].

Code:

var a = [], b = [];
for (var key in data) {
  a.push(getIntPart(key));
  b.push(data[key]);
}

function getIntPart(key) {
  key = key.substring(4); //Remove DAYS word
  return parseInt(key);
} 

I think key.substring(4) is not the right way to do it because it will fail for some other key. Please suggest how should I solve this issue.

Answer 1

You may use regular expression:

key = (key.match(/\d+$/) || []).pop();

This will match all numbers (\d+) at the end ($) of key string.

Answer 2

If it's only every "DAYS" you need to remove use a simple replace:

a.push(+k.replace('DAYS', ''));

Fiddle

Or, using your example:

function getIntPart(key) {
  key = key.replace('DAYS', '');
  return parseInt(key);
}

Answer 3

Alternatively you can use split here and extract the second token:

key = key.split(/(\d+)/)[1]