function assocHas(array, key) {
	  return assocIndexOf(array, key) > -1;
	}
Checks if an associative array value for `key` exists.

@private
@param {Array} array The array to query.
@param {string} key The key of the entry to check.
@returns {boolean} Returns `true` if an entry for `key` exists, else `false`.