Finding numbers in a string and adding them together

Question

I was wondering if it were possible with jQuery to add together numbers in a string...

The strings can only be added to themselves as shown in the examples below. If one or more of the string appears, it should be combined.

All the possible strings: click here

Example with possible strings:

+0.53 attack damage
+0.53 attack damage
= 1.06 attack damage

+8.75 mana
+8.75 mana
= 17.5 mana

Each of these can be combined up to 9 times.

look at http://stackoverflow.com/questions/3955345/javascript-jquery-get-number-from-string — , Aug 18 '14 at 12:03
@AnoopJoshi - no the string would be different almost every time — SaiyanToaster, Aug 18 '14 at 12:04
what is source of strings, are they being concatenated with numbers at server? — charlietfl, Aug 18 '14 at 12:05
@terribleProgrammer - this is an example of always having the same thing before the number? I'm talking about random strings from a set. — SaiyanToaster, Aug 18 '14 at 12:05
@charlietfl here is a list of all the possible strings: http://testing.lolnode.com/lol/show_desc.html — SaiyanToaster, Aug 18 '14 at 12:08
those calculations are being done somewhere, so link doesn't answer my question. If numbers get stored into data attributes can simplify problem — charlietfl, Aug 18 '14 at 12:10
@charlietfl O, right, no the numbers will be part of the string, only the whole string will be stored as a variable. — SaiyanToaster, Aug 18 '14 at 12:11

score 1 · Answer 1 · answered Aug 18 '14 at 12:05

Iterate through the characters of the string (by making substrings with length 1); once you detect a number or a decimal point, save the start position in a variable. Then, once you detect something that is not a number or decimal point, or a second decimal point (count the number of decimal points), the number has ended; save the end position and voilà, you have the start and end position of the number and can get it by making a substring.

this should be posted as a comment not an answer. – SaiyanToaster Aug 18 '14 at 12:14 — SaiyanToaster, Aug 18 '14 at 12:14

Samuli Hakoniemi · Answer 2 · 2014-08-18T12:26:22.793

0

var strs = [
  "Hello 1 World",
  "Hello 2 World"
];

var n = 0;
strs.forEach(function(str) {
  str.match(/[\d|\.|\-]+/g).forEach(function(num) {
    n+= window.parseFloat(num);
  });
});

Edit: Oh, that "list of possible strings" (with percentage values etc) changed the game. Well, start with this and improve the implementation :|

edited Aug 18 '14 at 12:26

answered Aug 18 '14 at 12:07

Samuli Hakoniemi

18,740
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i've added a list of all the possible strings, this might help you. – SaiyanToaster Aug 18 '14 at 12:09

score 0 · Accepted Answer · answered Aug 18 '14 at 12:18

With this regex:

/((-|\+)?([0-9]+|)(\.?[0-9]+))/g

You can use Array.prototype.reduce like this to sum your numbers up

var str = 'Hello +0.50 World Hello 1 World Hello -10 World',
    re = /((-|\+)?([0-9]+|)(\.?[0-9]+))/g,
    sum;

sum = (str.match(re) || []).reduce(function (prev, current) {
   if (Object.prototype.toString.call(prev) !== '[object Number]') {
       prev = parseFloat(prev, 10);
   }
   return prev + parseFloat(current, 10);
}, 0);

// sum should be equal to -8.5 here

Note that str.match(re) may return null, so we just make sure we call reduce on an array.

Would it be possible to ignore things within brackets? Example: `+0.3 health per level (+5.4 at champion level 18)` ignore `(+5.4 at champion level 18)` — SaiyanToaster, Aug 18 '14 at 12:43

Finding numbers in a string and adding them together

3 Answers3

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