Javascript get number from string-CodePudding

I have this an example:

const str = "Icecream, Milk, vanilla syrup, ice cubes20.0 SR180 calories"

I need a way to get the 20.0 from the string, it is always positioned before SR

I tried to convert the string to array like so:

const strArr = str.split(' ');

and try to get the index of the object contain SR

const index = strArr.map((object) => object).indexOf('SR');

But it showed me a result of -1

I was thinking to get the element by index - 1 to have the result of 20.0

Any other ideas, how to make it properly?

Thanks

CodePudding user response：

If you're gonna split do it on SR. Then extract the digits from the end of the first string.

const str = "Icecream, Milk, vanilla syrup, ice cubes20.0 SR180 calories"
var arr = str.split("SR");
var rev = arr[0].trim().split("");
var num = []
while (rev.length) {
  var char = rev.pop();
  if (!(char >= '0' && char <= '9' || char == ".")) {
    break;
  }
  num.push(char);
}
var result = num.reverse().join("");
console.log(result)

CodePudding user response：

I think this might help:

const finalNumber = str.split(' SR')[0].trim().split(' ').pop().replace(/[^\d.]/g, '');
console.log(finalNumber);

EDITED:

console.log("final", str.split('SR')[0].replace(/[^\d.]/g, '').split('.').slice(-2).join('.'))

CodePudding user response：

We can use match with following regexp:

const str = "Black coffee preparing with v60 filter18.00 SR38 Calories"
const res = str.match(/\d (.\d )?(?= SR)/g)
console.log(res[0])

Regexp explain:

\d - will match any string of digits,
(.\d )? - will match floating point (optionally thanks to ?),
(?= SR) - will match a group after main expression without including it in results.