TypeScript gives error if instead of returning value throws Error
I have this function:
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
this.objectCollector.forEach( object => {
if(object.getID() === id){
return object;
}
});
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
And I get the following ts error:
Not all code paths return a value.
That's true, because object.id must not be in objectCollector Array, in which case I throw an Error. How could I make this work? I've tried doing
public getObject(obj:IObjectsCommonJSON): ObjectsCommon | void
But it does not work either
javascript function typescript typescript-typings
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
add a comment |
I have this function:
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
this.objectCollector.forEach( object => {
if(object.getID() === id){
return object;
}
});
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
And I get the following ts error:
Not all code paths return a value.
That's true, because object.id must not be in objectCollector Array, in which case I throw an Error. How could I make this work? I've tried doing
public getObject(obj:IObjectsCommonJSON): ObjectsCommon | void
But it does not work either
javascript function typescript typescript-typings
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
Tryreturn this.objectCollector.......
– Banujan Balendrakumar
Nov 21 '18 at 17:48
return in forEach?
– epascarello
Nov 21 '18 at 18:06
1
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07
add a comment |
I have this function:
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
this.objectCollector.forEach( object => {
if(object.getID() === id){
return object;
}
});
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
And I get the following ts error:
Not all code paths return a value.
That's true, because object.id must not be in objectCollector Array, in which case I throw an Error. How could I make this work? I've tried doing
public getObject(obj:IObjectsCommonJSON): ObjectsCommon | void
But it does not work either
javascript function typescript typescript-typings
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
I have this function:
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
this.objectCollector.forEach( object => {
if(object.getID() === id){
return object;
}
});
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
And I get the following ts error:
Not all code paths return a value.
That's true, because object.id must not be in objectCollector Array, in which case I throw an Error. How could I make this work? I've tried doing
public getObject(obj:IObjectsCommonJSON): ObjectsCommon | void
But it does not work either
javascript function typescript typescript-typings
javascript function typescript typescript-typings
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
asked Nov 21 '18 at 17:39
Alberto ValeroAlberto Valero
486
486
Tryreturn this.objectCollector.......
– Banujan Balendrakumar
Nov 21 '18 at 17:48
return in forEach?
– epascarello
Nov 21 '18 at 18:06
1
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07
add a comment |
Tryreturn this.objectCollector.......
– Banujan Balendrakumar
Nov 21 '18 at 17:48
return in forEach?
– epascarello
Nov 21 '18 at 18:06
1
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07
Try
return this.objectCollector.......– Banujan Balendrakumar
Nov 21 '18 at 17:48
Try
return this.objectCollector.......– Banujan Balendrakumar
Nov 21 '18 at 17:48
return in forEach?
– epascarello
Nov 21 '18 at 18:06
return in forEach?
– epascarello
Nov 21 '18 at 18:06
1
1
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07
add a comment |
2 Answers
2
active
oldest
votes
The error is inside the callback to forEach(), not on the getObject() call. Note that even though you are using an arrow function, it's still a function. And the return inside the callback is returning from the arrow function, not from getObject(). Note that for arrow functions, x => {return y} is equivalent to x => y. There's no way to return from an outer function from inside an arrow function.
So this is your function:
object => {
if(object.getID() === id){
return object;
}
}
And the compiler (if you've enabled --noImplicitReturns) notices that this function only sometimes returns a value, and so it complains.
Of course, forEach() doesn't care about the return value of its callback, and that wasn't your intent anyway. The fix is to do what others have suggested... use find() instead of forEach(): ... this.objectCollector.find(o => o.getID()===id) ... Or use a for loop:
for (let object of this.objectCollector) {
if (object.getID() === id) {
return object; // no callback, this returns from the getObject function.
}
}
Hope that helps; good luck!
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
add a comment |
I would use find() and add if check to throw the error.
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
const item = this.objectCollector.find(object => object.getID() === id);
if (!item) {
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
return item;
}
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
The error is inside the callback to forEach(), not on the getObject() call. Note that even though you are using an arrow function, it's still a function. And the return inside the callback is returning from the arrow function, not from getObject(). Note that for arrow functions, x => {return y} is equivalent to x => y. There's no way to return from an outer function from inside an arrow function.
So this is your function:
object => {
if(object.getID() === id){
return object;
}
}
And the compiler (if you've enabled --noImplicitReturns) notices that this function only sometimes returns a value, and so it complains.
Of course, forEach() doesn't care about the return value of its callback, and that wasn't your intent anyway. The fix is to do what others have suggested... use find() instead of forEach(): ... this.objectCollector.find(o => o.getID()===id) ... Or use a for loop:
for (let object of this.objectCollector) {
if (object.getID() === id) {
return object; // no callback, this returns from the getObject function.
}
}
Hope that helps; good luck!
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
add a comment |
The error is inside the callback to forEach(), not on the getObject() call. Note that even though you are using an arrow function, it's still a function. And the return inside the callback is returning from the arrow function, not from getObject(). Note that for arrow functions, x => {return y} is equivalent to x => y. There's no way to return from an outer function from inside an arrow function.
So this is your function:
object => {
if(object.getID() === id){
return object;
}
}
And the compiler (if you've enabled --noImplicitReturns) notices that this function only sometimes returns a value, and so it complains.
Of course, forEach() doesn't care about the return value of its callback, and that wasn't your intent anyway. The fix is to do what others have suggested... use find() instead of forEach(): ... this.objectCollector.find(o => o.getID()===id) ... Or use a for loop:
for (let object of this.objectCollector) {
if (object.getID() === id) {
return object; // no callback, this returns from the getObject function.
}
}
Hope that helps; good luck!
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
add a comment |
The error is inside the callback to forEach(), not on the getObject() call. Note that even though you are using an arrow function, it's still a function. And the return inside the callback is returning from the arrow function, not from getObject(). Note that for arrow functions, x => {return y} is equivalent to x => y. There's no way to return from an outer function from inside an arrow function.
So this is your function:
object => {
if(object.getID() === id){
return object;
}
}
And the compiler (if you've enabled --noImplicitReturns) notices that this function only sometimes returns a value, and so it complains.
Of course, forEach() doesn't care about the return value of its callback, and that wasn't your intent anyway. The fix is to do what others have suggested... use find() instead of forEach(): ... this.objectCollector.find(o => o.getID()===id) ... Or use a for loop:
for (let object of this.objectCollector) {
if (object.getID() === id) {
return object; // no callback, this returns from the getObject function.
}
}
Hope that helps; good luck!
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
The error is inside the callback to forEach(), not on the getObject() call. Note that even though you are using an arrow function, it's still a function. And the return inside the callback is returning from the arrow function, not from getObject(). Note that for arrow functions, x => {return y} is equivalent to x => y. There's no way to return from an outer function from inside an arrow function.
So this is your function:
object => {
if(object.getID() === id){
return object;
}
}
And the compiler (if you've enabled --noImplicitReturns) notices that this function only sometimes returns a value, and so it complains.
Of course, forEach() doesn't care about the return value of its callback, and that wasn't your intent anyway. The fix is to do what others have suggested... use find() instead of forEach(): ... this.objectCollector.find(o => o.getID()===id) ... Or use a for loop:
for (let object of this.objectCollector) {
if (object.getID() === id) {
return object; // no callback, this returns from the getObject function.
}
}
Hope that helps; good luck!
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
answered Nov 21 '18 at 18:31
jcalzjcalz
30.3k22850
30.3k22850
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
add a comment |
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
Thanks for the explanation @jcalz . Now it's clear!!
– Alberto Valero
Nov 21 '18 at 18:46
add a comment |
I would use find() and add if check to throw the error.
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
const item = this.objectCollector.find(object => object.getID() === id);
if (!item) {
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
return item;
}
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
add a comment |
I would use find() and add if check to throw the error.
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
const item = this.objectCollector.find(object => object.getID() === id);
if (!item) {
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
return item;
}
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
add a comment |
I would use find() and add if check to throw the error.
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
const item = this.objectCollector.find(object => object.getID() === id);
if (!item) {
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
return item;
}
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
I would use find() and add if check to throw the error.
public getObject(obj:IObjectsCommonJSON): ObjectsCommon {
const id = obj.id;
const item = this.objectCollector.find(object => object.getID() === id);
if (!item) {
throw new Error(`Scene.getObject(). Object ${id} not found`);
}
return item;
}
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
answered Nov 21 '18 at 18:21
epascarelloepascarello
154k14138187
154k14138187
add a comment |
add a comment |
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Try
return this.objectCollector.......– Banujan Balendrakumar
Nov 21 '18 at 17:48
return in forEach?
– epascarello
Nov 21 '18 at 18:06
1
Why are you not using find() ?
– epascarello
Nov 21 '18 at 18:07