Create a class car with a constructor function which accepts 2 parameters (name and distance). Include a prototype method in class, which returns a message(msg) "car name(name) had travelled for distance(distance) miles".
I know its a very simple question, but I guess I am not able to design the code well, though it is giving me the right result yet I believe as per standards it is not right??
class Car {
constructor(name, distance) {
this.name = name;
this.distance = distance;
}
lengthMiles() {
console.log(`${this.name} had travelled for ${this.distance} miles`)
}
}
var msg = new Car('Audi', 100);
msg.lengthMiles();
class Car {
constructor(name, distance) {
this.name = name;
this.distance = distance;
}
carDistance() {
return `${this.name} had travelled for ${this.distance} miles`;
}
}
let Car1 = new Car('Audi', 100);
const msg = Car1.carDistance();
console.log(msg);
module.exports = {msg}
The problem statement reads:
Include a prototype method in class, which returns a message(msg) "car name(name) had travelled for distance(distance) miles".
Which should mean that the method actually uses return instead of printing to the console.
class Car {
constructor(name, distance) {
this.name = name;
this.distance = distance;
}
lengthMiles() {
return `${this.name} had travelled for ${this.distance} miles`;
// ^^^^^^ --------------------------- using a return statement
} // |
} // |
// |
var car = new Car('Audi', 100);// |
var msg = car.lengthMiles(); // |
console.log(msg);// <----------------- printing the message here
100% working code you will pass the TEST.
Below is the correct code.Just copy as it is and replace in editor and test it.
After testing please dont forget to hit like and share the answer.
class Car {
constructor(name, distance) {
this.name = name;
this.distance = distance;
}
carDistance() {
return `${this.name} had travelled for ${this.distance} miles`;
}
}
let Car1 = new Car('Audi', 100);
const msg = Car1.carDistance();
console.log(msg);
module.exports = {msg}
Related
Suppose a JSON column called blob in a MySQL 5.7 database table called "Thing" with the following content:
[
{
"id": 1,
"value": "blue"
},
{
"id": 2,
"value": "red"
}
]
Is it possible to select all records from Thing where the blob contains an object within the array where the id is some dynamic value and the value is also some dynamic value.
E.g. "give me all Things where the blob contains an object whose id is 2 and value is 'red'"
Not sure how to form the WHERE clause below:
SET #id = 2;
SET #value1 = 'red';
SET #value2 = 'blue';
-- with equals?
SELECT *
FROM Thing
WHERE JSON_EXTRACT(blob, '$[*].id ... equals #id ... and .value') = #value1;
-- with an IN clause?
SELECT *
FROM Thing
WHERE JSON_EXTRACT(blob, '$[*].id ... equals #id ... and .value') IN (#value1, #value2);
They said it couldn't be done. They told me I was a fool. Lo and behold, I have done it!
Here are some helper functions to teach Hibernate how to perform JSON functions against a MySQL 5.7 backend, and an example use case. It's confusing, for sure, but it works.
Context
This contrived example is of a Person entity which can have many BioDetails, which is a question/answer type (but is more involved than that). The example within below essentially is searching within two JSON payloads, grabbing JSON values from one to build JSON paths within which to search in the other. In the end, you can pass in a complex structure of AND'd or OR'd criteria, which will be applied against a JSON blob and return only the resulting rows which match.
E.g. give my all Person entities where their age is > 30 and their favorite color is blue or orange. Given that those key/value pairs are stored in a JSON blob, you can find those matched using the example code below.
JSON-search classes and example repo
Classes below use Lombok for brevity.
Classes to allow specification of search criteria
SearchCriteriaContainer
#Data
#EqualsAndHashCode
public class SearchCriteriaContainer
{
private List<SearchCriterion> criteria;
private boolean and;
}
SearchCriterion
#Data
#EqualsAndHashCode(callSuper = true)
public class SearchCriterion extends SearchCriteriaContainer
{
private String field;
private List<String> values;
private SearchOperator operator;
private boolean not = false;
}
SearchOperator
#RequiredArgsConstructor
public enum SearchOperator
{
EQUAL("="),
LESS_THAN("<"),
LESS_THAN_OR_EQUAL("<="),
GREATER_THAN(">"),
GREATER_THAN_OR_EQUAL(">="),
LIKE("like"),
IN("in"),
IS_NULL("is null");
private final String value;
#JsonCreator
public static SearchOperator fromValue(#NotBlank String value)
{
return Stream
.of(SearchOperator.values())
.filter(o -> o.getValue().equals(value))
.findFirst()
.orElseThrow(() ->
{
String message = String.format("Could not find %s with value: %s", SearchOperator.class.getName(), value);
return new IllegalArgumentException(message);
});
}
#JsonValue
public String getValue()
{
return this.value;
}
#Override
public String toString()
{
return value;
}
}
Helper class which is used to call JSON functions
#RequiredArgsConstructor
public class CriteriaBuilderHelper
{
private final CriteriaBuilder criteriaBuilder;
public Expression<String> concat(Expression<?>... values)
{
return criteriaBuilder.function("CONCAT", String.class, values);
}
public Expression<String> substringIndex(Expression<?> value, String delimiter, int count)
{
return substringIndex(value, criteriaBuilder.literal(delimiter), criteriaBuilder.literal(count));
}
public Expression<String> substringIndex(Expression<?> value, Expression<String> delimiter, Expression<Integer> count)
{
return criteriaBuilder.function("SUBSTRING_INDEX", String.class, value, delimiter, count);
}
public Expression<String> jsonUnquote(Expression<?> jsonValue)
{
return criteriaBuilder.function("JSON_UNQUOTE", String.class, jsonValue);
}
public Expression<String> jsonExtract(Expression<?> jsonDoc, Expression<?> path)
{
return criteriaBuilder.function("JSON_EXTRACT", String.class, jsonDoc, path);
}
public Expression<String> jsonSearchOne(Expression<?> jsonDoc, Expression<?> value, Expression<?>... paths)
{
return jsonSearch(jsonDoc, "one", value, paths);
}
public Expression<String> jsonSearch(Expression<?> jsonDoc, Expression<?> value, Expression<?>... paths)
{
return jsonSearch(jsonDoc, "all", value, paths);
}
public Expression<String> jsonSearch(Expression<?> jsonDoc, String oneOrAll, Expression<?> value, Expression<?>... paths)
{
if (!"one".equals(oneOrAll) && !"all".equals(oneOrAll))
{
throw new RuntimeException("Parameter 'oneOrAll' must be 'one' or 'all', not: " + oneOrAll);
}
else
{
final var expressions = new ArrayList<>(List.of(
jsonDoc,
criteriaBuilder.literal(oneOrAll),
value,
criteriaBuilder.nullLiteral(String.class)));
if (paths != null)
{
expressions.addAll(Arrays.asList(paths));
}
return criteriaBuilder.function("JSON_SEARCH", String.class, expressions.toArray(Expression[]::new));
}
}
}
Utility to turn SearchCriteria into MySQL JSON function calls
SearchHelper
public class SearchHelper
{
private static final Pattern pathSeparatorPattern = Pattern.compile("\\.");
public static String getKeyPart(String key)
{
return pathSeparatorPattern.split(key)[0];
}
public static String getPathPart(String key)
{
final var parts = pathSeparatorPattern.split(key);
final var path = new StringBuilder();
for (var i = 1; i < parts.length; i++)
{
if (i > 1)
{
path.append(".");
}
path.append(parts[i]);
}
return path.toString();
}
public static Optional<Predicate> getCriteriaPredicate(SearchCriteriaContainer container, CriteriaBuilder cb, Path<String> bioDetailJson, Path<String> personJson)
{
final var predicates = new ArrayList<Predicate>();
if (container != null && container.getCriteria() != null && container.getCriteria().size() > 0)
{
final var h = new CriteriaBuilderHelper(cb);
container.getCriteria().forEach(ac ->
{
final var groupingOnly = ac.getField() == null && ac.getOperator() == null;
// a criterion can be used for grouping other criterion, and might not have a field/operator/value
if (!groupingOnly)
{
final var key = getKeyPart(ac.getField());
final var path = getPathPart(ac.getField());
final var bioDetailQuestionKeyPathEx = h.jsonUnquote(h.jsonSearchOne(bioDetailJson, cb.literal(key), cb.literal("$[*].key")));
final var bioDetailQuestionIdPathEx = h.concat(h.substringIndex(bioDetailQuestionKeyPathEx, ".", 1), cb.literal(".id"));
final var questionIdEx = h.jsonUnquote(h.jsonExtract(bioDetailJson, bioDetailQuestionIdPathEx));
final var answerPathEx = h.substringIndex(h.jsonUnquote(h.jsonSearchOne(personJson, questionIdEx, cb.literal("$[*].questionId"))), ".", 1);
final var answerValuePathEx = h.concat(answerPathEx, cb.literal("." + path));
final var answerValueEx = h.jsonUnquote(h.jsonExtract(personJson, answerValuePathEx));
switch (ac.getOperator())
{
case IN:
{
final var inEx = cb.in(answerValueEx);
if (ac.getValues() == null || ac.getValues().size() == 0)
{
throw new RuntimeException("No values provided for 'IN' criteria for field: " + ac.getField());
}
else
{
ac.getValues().forEach(inEx::value);
}
predicates.add(inEx);
break;
}
case IS_NULL:
{
predicates.add(cb.isNull(answerValueEx));
break;
}
default:
{
if (ac.getValues() == null || ac.getValues().size() == 0)
{
throw new RuntimeException("No values provided for '" + ac.getOperator() + "' criteria for field: " + ac.getField());
}
else
{
ac.getValues().forEach(value ->
{
final var valueEx = cb.literal(value);
switch (ac.getOperator())
{
case EQUAL:
{
predicates.add(cb.equal(answerValueEx, valueEx));
break;
}
case LESS_THAN:
{
predicates.add(cb.lessThan(answerValueEx, valueEx));
break;
}
case LESS_THAN_OR_EQUAL:
{
predicates.add(cb.lessThanOrEqualTo(answerValueEx, valueEx));
break;
}
case GREATER_THAN:
{
predicates.add(cb.greaterThan(answerValueEx, valueEx));
break;
}
case GREATER_THAN_OR_EQUAL:
{
predicates.add(cb.greaterThanOrEqualTo(answerValueEx, valueEx));
break;
}
case LIKE:
{
predicates.add(cb.like(answerValueEx, valueEx));
break;
}
default:
throw new RuntimeException("Unsupported operator during snapshot search: " + ac.getOperator());
}
});
}
}
}
}
// iterate nested criteria
getAnswerCriteriaPredicate(ac, cb, bioDetailJson, personJson).ifPresent(predicates::add);
});
return Optional.of(container.isAnd()
? cb.and(predicates.toArray(Predicate[]::new))
: cb.or(predicates.toArray(Predicate[]::new)));
}
else
{
return Optional.empty();
}
}
}
Example JPA Specification repository / search method
ExampleRepository
#Repository
public interface PersonRepository extends JpaSpecificationExecutor<Person>
{
default Page<Person> search(PersonSearchDirective directive, Pageable pageable)
{
return findAll((person, query, cb) ->
{
final var bioDetail = person.join(Person_.bioDetail);
final var bioDetailJson = bioDetail.get(BioDetailEntity_.bioDetailJson);
final var personJson = person.get(Person_.personJson);
final var predicates = new ArrayList<>();
SearchHelper
.getCriteriaPredicate(directive.getSearchCriteria(), cb, bioDetailJson, personJson)
.ifPresent(predicates::add);
return cb.and(predicates.toArray(Predicate[]::new));
}, pageable);
}
}
I am building an android application that shows autocomplete feature and fetches autocomplete predictions in google maps using - GeoDataApi.getAutocompletePredictions. I followed this tutorial - https://github.com/googlesamples/android-play-places/blob/master/PlaceComplete/Application/src/main/java/com/example/google/playservices/placecomplete/PlaceAutocompleteAdapter.java
But somehow this is not working fine for me.
My class is this -
public class GooglePlacesAutoCompleteAdapter extends ArrayAdapter implements Filterable {
private ArrayList<PlaceAutocomplete> mResultList;
GoogleApiClient mGoogleApiClient;
private LatLngBounds mBounds;
private AutocompleteFilter mPlaceFilter;
int radius = 500;
public GooglePlacesAutoCompleteAdapter(Context context, int textViewResourceId, GoogleApiClient googleApiClient,
Location lastLocation, AutocompleteFilter filter) {
super(context, textViewResourceId);
LatLng currentLatLng = new LatLng(lastLocation.getLatitude(), lastLocation.getLongitude());
mBounds = Utility.boundsWithCenterAndLatLngDistance(currentLatLng, 500, 500);
mGoogleApiClient = googleApiClient;
mPlaceFilter = filter;
}
#Override
public int getCount() {
return mResultList.size();
}
#Override
public PlaceAutocomplete getItem(int index) {
return mResultList.get(index);
}
#Override
public android.widget.Filter getFilter() {
Filter filter = new Filter() {
#Override
public FilterResults performFiltering(CharSequence constraint) {
FilterResults filterResults = new FilterResults();
if (constraint != null && constraint.length() > 3 && constraint.length()%3 == 1) {
// Retrieve the autocomplete results.
mResultList = autocomplete(constraint.toString());
// Assign the data to the FilterResults
filterResults.values = mResultList;
filterResults.count = mResultList.size();
}
return filterResults;
}
#Override
public void publishResults(CharSequence constraint, FilterResults results) {
if (results != null && results.count > 0) {
notifyDataSetChanged();
} else {
notifyDataSetInvalidated();
}
}
};
return filter;
}
public ArrayList<PlaceAutocomplete> autocomplete(String input) {
if (mGoogleApiClient.isConnected()) {
// Submit the query to the autocomplete API and retrieve a PendingResult that will
// contain the results when the query completes.
PendingResult results = Places.GeoDataApi.getAutocompletePredictions(mGoogleApiClient, input.toString(),
mBounds, mPlaceFilter);
// This method should have been called off the main UI thread. Block and wait for at most 60s
// for a result from the API.
AutocompletePredictionBuffer autocompletePredictions = (AutocompletePredictionBuffer)results.await(60, TimeUnit.SECONDS);
// Confirm that the query completed successfully, otherwise return null
final Status status = autocompletePredictions.getStatus();
if (!status.isSuccess()) {
//Toast.makeText(getContext(), "Error contacting API: " + status.toString(),Toast.LENGTH_SHORT).show();
//Log.e(TAG, "Error getting autocomplete prediction API call: " + status.toString());
autocompletePredictions.release();
return null;
}
// Copy the results into our own data structure, because we can't hold onto the buffer.
// AutocompletePrediction objects encapsulate the API response (place ID and description).
Iterator<AutocompletePrediction> iterator = autocompletePredictions.iterator();
ArrayList resultList = new ArrayList<>(autocompletePredictions.getCount());
while (iterator.hasNext()) {
AutocompletePrediction prediction = iterator.next();
// Get the details of this prediction and copy it into a new PlaceAutocomplete object.
resultList.add(new PlaceAutocomplete(prediction.getPlaceId(), prediction.getDescription()));
}
// Release the buffer now that all data has been copied.
autocompletePredictions.release();
return resultList;
}
//Log.e(TAG, "Google API client is not connected for autocomplete query.");
return null;
}
class PlaceAutocomplete {
public CharSequence placeId;
public CharSequence description;
PlaceAutocomplete(CharSequence placeId, CharSequence description) {
this.placeId = placeId;
this.description = description;
}
#Override
public String toString() {
return description.toString();
}
}
}
The line on which GeoDataApi.getAutocompletePredictions is called, goes into an internal classes called - Filter.java, Log.java, handler.java and then Looper.java and loops there indefinetly on line 121 of Looper.java (I am sure studio sdk will show the code for Looper.java).
It is not even throwing an error, or going to the next line, it just does not work. Plus, I am not able to see the stack trace of an error.
This is the code snippet which is calling this -
if (mLastLocation != null) {
GooglePlacesAutoCompleteAdapter placesAdapter = new GooglePlacesAutoCompleteAdapter(this, R.layout.item_list, mGoogleApiClient, mLastLocation, null);
autoCompView.setAdapter(placesAdapter);
autoCompView.setOnItemClickListener(this);
}
Can someone please tell me what I am doing wrong here? Please any help will be greatly appreciated. I need to get this working as soon as I could.
PS - I am passing mPlaceFilter as null here.
Enable the Google Places API for Android in developers console
I want to update the value of _third.data["#ID"] in this code. What i want to do it to add something with _third.data["#ID"] when storing it in this.ID
What i want to do is:
this.ID = "myvalue" + _third.data["#ID"];
but in output i get myvalueundefined but if i remove "myvalue" from code thn it works fine and gives me the correct value please help me my knowledge of actionscript isn't that much i just learned some of it from internet.
Here is the coding:
public function main(_first:String, _second:Array, _third:SharedObject):Object{
this.ID = _third.data["#ID"];
};
What i want to do is:
public function main(_first:String, _second:Array, _third:SharedObject):Object{
this.ID = "myvalue" + _third.data["#ID"];
};
Using your code, I created the below test case. It's doing the same as your code, and is outputting the expected values.
package kazo
{
import flash.net.SharedObject;
/**
* ...
* #author KM
*/
public class TestCases
{
private var ID :String = null;
public function TestCases() { }
/**
* Start the test case
*/
public function start():void {
trace('Starting test case');
var SO:SharedObject = SharedObject.getLocal('TestCases');
if (!SO.data["#ID"]) {
trace('SO data not found, creating');
SO.data["#ID"] = '123';
SO.flush();
}
getID(SO);
}
/**
*
* #param _SO
*/
public function getID(_SO:SharedObject):void {
this.ID = "myvalue" + _SO.data["#ID"];
// trace = myvalue123
trace(this.ID);
}
}
}
trace:
(fcsh)Build succeeded
Done(0)
[Starting debug session with FDB]
Starting test case
myvalue123
If you're still having problems, I'd suggest trying to call toString() on the value you're pulling, so:
this.ID = "myvalue" + _SO.data["#ID"].toString();
Should that still not work, store it in two separate String variables and then combined them.
class Foo {
public function bar():void { ... }
}
var clazz:Class = Foo;
// ...enter the function (no Foo literal here)
var fun:Function = clazz["bar"]; // PROBLEM: returns null
// later
fun.call(new Foo(), ...);
What is the correct way to do the above? The Java equivalent of what I want to do is:
Method m = Foo.class.getMethod("bar", ...);
m.invoke(new Foo(), ...);
Actual code (with workaround):
class SerClass {
public var className:String;
public var name:String;
private var ser:String = null;
private var unser:Function = null;
public function SerClass(clazz:Class):void {
var type:XML = describeType(clazz);
className = type.#name;
// determine name
name = type.factory.metadata.(#name=="CompactType").arg.(#key=="name").#value;
// find unserializer
var mdesc:XML = XML(type.method.metadata.(#name=="Unserialize")).parent();
if (mdesc is XML) {
unser = clazz[mdesc.#name];
}
// find serializer
var sdesc:XML = XML(type.factory.method.metadata.(#name=="Serialize")).parent();
if (sdesc is XML) {
ser = sdesc.#name;
}
}
public function serialize(obj:Object, ous:ByteArray):void {
if (ser == null) throw new Error(name + " is not serializable");
obj[ser](ous);
}
public function unserialize(ins:ByteArray):Object {
if (unser == null) throw new Error(name + " is not unserializable");
return unser.call(null, ins);
}
}
Here the function bar only exist when your class is instanciated :
var foo:Foo = new Foo()
var fun:Function = foo.bar // <-- here you can get the function from the new instance
if you want to access it directlty you have to make it static:
class Foo {
public static function bar():void{ ... }
}
now you can access your function from the class Foo:
var fun:Function = Foo.bar
or
var clazz:Class = Foo
var fun:Function = clazz["bar"]
I am not sure about what you are intending to do.
However AS3Commons, especially the reflect package have API's that let you work with methods, instances and properties of a class.
There are also API methods to create instances of certain class types on the fly and call their respective methods.
Cheers
It's not
fun.call(new Foo(), ...);
Use instead since no parameters are required for the function
fun.call(clazz);
The first parameter as specified by adobe docs.
An object that specifies the value of thisObject within the function body.
[EDIT]
Forgot to point out you have to instantiate a non-static class with the "new" keyword.
var clazz:Class = new Foo();
[EDIT2]
Ok I played around and think I got what you want.
base.as
package{
public class Base {
public function Base() {
trace('Base constructor')
}
public function someFunc( ){
trace('worked');
}
}
}
//called with
var b:Base = new Base( );// note I am not type casting to Class
var func:Function = b.someFunc;
func.call( );
My workaround is to store the function name instead of the Function object.
var fun:String = "bar";
// later...
new Foo()[fun](...);
i'd like to throw an argument error if a particular function doesn't work without a passed value that also happens to be a public constant of the class containing the function.
is there anyway to determine if a class owns a public constant instead of having to iterate thru all of them?
something like this:
public static const HALIFAX:String = "halifax";
public static const MONTREAL:String = "montreal";
public static const TORONTO:String = "toronto";
private var cityProperty:String;
public function set city(value:String):void
{
if (!this.hasConstant(value))
throw new ArgumentError("set city value is not applicable.");
cityProperty = value;
}
public function get city():Strig
{
return cityProperty;
}
currently, for this functionality i have to write the city setter function like this:
public function set city(value:String):void
{
if (value != HALIFAX && value != MONTREAL && value != TORONTO)
throw new ArgumentError("set city value is not applicable.");
cityProperty = value;
}
is this the only way to accomplish this task?
Yes, if you use reflections:
private var type:Class;
private var description:XML;
private function hasConstant (str : String ) : Boolean
{
if (description == null)
{
type = getDefinitionByName (getQualifiedClassName (this)) as Class;
description = describeType (type);
}
for each ( var constant:XML in description.constant)
{
if (type[constant.#name] == str) return true;
}
return false;
}
Note that for this to work, all constants must always be String objects declared public static const.
I was looking for an answer to this question myself and found it annoying that hasOwnProperty() did not work for static properties. Turns out though, that if you cast your class to a Class object, it does work.
Here's an example:
public final class DisplayMode
{
public static const one: String = "one";
public static const two: String = "two";
public static const three: String = "three";
public static function isValid(aDisplayMode: String): Boolean {
return Class(DisplayMode).hasOwnProperty(aDisplayMode);
}
}
I owe this solution to jimmy5804 from this discussion, so hats off to him.
You should be able to use bracket notation to do this. For example:
var foo:Sprite = new Sprite();
foo.rotation = 20;
trace( foo["x"], foo["rotation"]); // traces "0 20"
or more specific to your case:
var bar:String = "rotation";
trace( foo[bar] ); // traces "20"
The only thing you have to look out for here, is that the bracket accessor will throw a ReferenceError if you ask for an object property that isn't there, such as:
trace ( foo["cat"] ); // throws ReferenceError
But it will not throw if you are asking for a static property:
trace ( Sprite["cat"] ); // traces "undefined"
So in your case you might try:
if ( this[value] == undefined ) {
throw new ArgumentError("set city value is not applicable.");
}
EDIT:
Sorry, I was confusing the const's names with their values.
For this to work on your problem you would have to make the String value the same as the const's name, so for example:
public static const HALIFAX:String = "HALIFAX";
then you could use the query as described above and it would give you the desired result.