在特定索引后找到indexOf字符

Question

Pretty basic but I'm afraid I'm overlooking a simple solution. I have the following string ... IBAN: NL56INGB06716xxxxx ...

I need the accountnumber so I'm looking for indexOf("IBAN: ") but now I need to find the next space/whitespace char after that index.

I don't really think I would need a loop for this but it's the best I can come up with. Regex capture group maybe better? How would I do that?

Answer 1

From MDN String.prototype.indexOf

str.indexOf(searchValue[, fromIndex])

fromIndex Optional. The location within the calling string to start the search from. It can be any integer. The default value is 0 .

nb .indexOf will only look for a specific substring, if you want to find a choice from many characters, you will either need to loop and compare or use RegExp

---

Gracious example

var haystack = 'foo_ _IBAN: Bar _ _';
var needle = 'IBAN: ',
    i = haystack.indexOf(needle),
    j;
if (i === -1) {
    // no match, do something special
    console.warn('One cannot simply find a needle in a haystack');
}
j = haystack.indexOf(' ', i + needle.length);
// now we have both matches, we can do something fancy
if (j === -1) {
    j = haystack.length; // no match, set to end?
}
haystack.slice(i + needle.length, j); // "Bar"

Answer 2

While you can pass a starting index as Paul suggested, it would seem that a simple regex may just be easier.

var re = /IBAN:\s*(\S+)/

The capture group will hold the sequence of non-whitespace characters after the IBAN:

var match = re.exec(my_str)
if (match) {
    console.log(match[1]);
}