I'm looking for a contains like method for iterable [closed]

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Closed 8 years ago.

I have an Iterable and I need to check about a specific string inside the iterable. I tried iter.contains("my string"), but it does not work. Any idea?

Answer 1

try with

iter.toString().toLowerCase().equals("my string")

Answer 2

Iterable is an interface, it doesn't contain a method like contains because that would assume the underlying data structure could be read sequentially without corruption.

Neither are assumptions the Iterable interface makes.

Answer 3

Your only real option with a bare Iterable is to do a bare for loop:

 for (String string : iterable) {
   if (string.equals(foo)) {
     return true;
   }
 }
 return false;

...or you could call another method which does essentially the same thing, e.g. Guava's Iterables.contains(Iterable, Object).

Answer 4

The Interface Iterable only returns an Iterator. So it is not possible to directly obtain if a certain value is inside. Instead you have to iterate using a for-each structure e.g.

boolean found = false;
for (String s: iter) {
    if (s.equals("my string")) {
        found = true;
        break;
    }
 }

Depending on the Size this may not be very efficient. But if its your only choice...it will work at least.

Answer 5

try to create a iterator object and there is a contains method for iterators in most programming languages

This is a very similar question that has a been answered here Why does Iterator have a contains method but Iterable does not, in Scala 2.8?