find :: Enumerable

find(iterator) -> firstElement | undefined Finds the first element for which the iterator returns true. Convenience alias for detect, but constitutes the preferred (more readable) syntax.

This is the short-circuit version of the full-search findAll. It just returns the first element that matches your predicate, or undefined if no element matches.

Examples

// An optimal exact prime detection method, slightly compacted.

function isPrime(n) {

if (2 > n) return false;

if (0 == n % 2) return (2 == n);

for (var index = 3; n / index > index; index += 2)

if (0 == n % index) return false;

return true;

} // isPrime

$R(10,15).find(isPrime)

// -> 11

[ 'hello', 'world', 'this', 'is', 'nice'].find(function(s) {

return s.length <= 3;

})

// -> 'is'

Prototype API 1.5.0 - prototypejs.org