Using a String that contains operators as a variable on an if-statement

Question

Title is self-explanatory.

Instead of using:

if (link.contains(".com") || (link.contains(".net") || (link.contains(".org") || (link.contains(".info") || ("etc there are many domain names")) {
    webView.loadUrl("https://www." + link);
} else {
    webView.loadUrl("https://www." + link + ".com");
}

I want to do it this way if possible by declaring the String's values globally.

if (link.contains(domainNames)) {
    webView.loadUrl("https://www." + link);
} else {
    webView.loadUrl("https://www." + link + ".com");
}

This might help https://stackoverflow.com/questions/27110563/how-can-i-check-if-a-string-has-a-substring-from-a-list — Mark, Jul 03 '19 at 21:18
It is a bit unclear. You want to check which domain is in specific url without entering domains manually? — Yupi, Jul 03 '19 at 21:20

score 2 · Accepted Answer · answered Jul 03 '19 at 21:19

2

Build a regex with the domain names, then test it, e.g.

private static final Pattern DOMAIN_NAMES = Pattern.compile("\\.(?i:com|net|org|info)$");

if (DOMAIN_NAMES.matcher(link).find()) {
    webView.loadUrl("https://www." + link);
} else {
    webView.loadUrl("https://www." + link + ".com");
}

answered Jul 03 '19 at 21:19

Andreas

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Be warned, this is very error prone if two url endings happen to have mostly matching parts as a regex like e.g. `(a|abc)` will never match `abc` as the first alternatives consumes the `a` only leaving the `bc` to match, which won't happen now! You have to order your endings by length to avoid this issue – roookeee Jul 03 '19 at 21:32
1

@roookeee You are wrong, since the regex **backtracking** will ensure that `(a|abc)$` will match any string ending in `a` or `abc`. See [regex101](https://regex101.com/r/HJU7Mq/1) for proof. – Andreas Jul 03 '19 at 21:52
You are right, when using `$` this doesn't matter. It only matters in cases where one wants to have the most exact match (without using `$` at the end) as seen [here](https://regex101.com/r/gCjPie/1) – roookeee Jul 03 '19 at 22:53
This worked great. I use voice input to fill "link", it might be my imagination but i think voice searches are more accurate than before? anyway this is awesome... – Greg Jul 04 '19 at 09:05

score 0 · Answer 2 · answered Jul 04 '19 at 02:41

0

Another mannual approach could be : Domainnamelist.contains(substring from link that contains domain ending)

answered Jul 04 '19 at 02:41

Ashok Kumar

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Using a String that contains operators as a variable on an if-statement

2 Answers2