Cannot access this property under async function

Question

lookforcustomers(value){
  if (value == 'on') {
    var name = 'subash';

    this.intervalid = setInterval(async function getnearplaces(nameref) {
      console.log('running', this.name)

      //  console.log('loc',outerthis.state.lastknownlocation.latitude)

      // var driverpoint = new Parse.GeoPoint({latitude:this.ref.state.lastknownlocation.latitude, longitude:this.ref.state.lastknownlocation.longitude});
      //  var GameScore = Parse.Object.extend("Booking");
      // const query = new Parse.Query(PlaceObject);
      // query.equalTo("hired",false);
      // query.near("pick", driverpoint);
      // query.limit(1);
      //  const placesObjects = await query.find().then((object) => {
      //    console.log(object[0])
      //  }, (error) => {
      //
      //  console.log('error while looking for the customers')
      //  });

    }, 10000);
  }
}

I just need to access name-value from getnearplacesfuntion(). When I try to log the name value it is not printing. Is there any other procedure to access name value or is there any flaw in code above?

One more problem, you are calling this into `getnearplaces()` function, so `this` keyword represents for that. If you want to call like this, you should bind the keyword to the function `getnearplaces.bind(this)`. Sorry for my bad English — Thanh Dao, Nov 26 '19 at 04:14

score 0 · Answer 1 · answered Nov 26 '19 at 11:11

If you mean you want to access the value assigned to the variable name defined in this line:

var name = 'subash';

You simply need to omit the use of this as the inner function getnearplaces has access to variables defined in the context it is enclosed in.

So this:

console.log('running', name)

should print the string:

running subash

For better understanding of how closures work in JavaScript, you might want to read this: MDN - Closures

Hope this helps

score 0 · Answer 2 · answered Nov 26 '19 at 13:22

Try changing the async function to a arrow function:

lookforcustomers(value){
  if (value == 'on') {
    var name = 'subash';

    this.intervalid = setInterval(async (nameref) => {
      console.log('running', this.name)

      //  console.log('loc',outerthis.state.lastknownlocation.latitude)

      // var driverpoint = new Parse.GeoPoint({latitude:this.ref.state.lastknownlocation.latitude, longitude:this.ref.state.lastknownlocation.longitude});
      //  var GameScore = Parse.Object.extend("Booking");
      // const query = new Parse.Query(PlaceObject);
      // query.equalTo("hired",false);
      // query.near("pick", driverpoint);
      // query.limit(1);
      //  const placesObjects = await query.find().then((object) => {
      //    console.log(object[0])
      //  }, (error) => {
      //
      //  console.log('error while looking for the customers')
      //  });

    }, 10000);
  }
}

I hope this helped.

Cannot access this property under async function

2 Answers2