how i can to realize inheritance chain?
2
Have some problem with inheritance. How to implement type inheritance from Some Pencil to Another Pencil? Need: pen3.type // common
class Pencil
constructor(color)
this.color = color;
intro()
console.log(`this is $this.color pencil`);
;
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type;
;
class AnotherPencil extends SomePencil
constructor(color,type)
super(color, type);
;
let pen1 = new Pencil();
let pen2 = new SomePencil("red", "common");
let pen3 = new AnotherPencil("green");
console.log("type" in pen3); // true
javascript oop
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
|
show 1 more comment
2
Have some problem with inheritance. How to implement type inheritance from Some Pencil to Another Pencil? Need: pen3.type // common
class Pencil
constructor(color)
this.color = color;
intro()
console.log(`this is $this.color pencil`);
;
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type;
;
class AnotherPencil extends SomePencil
constructor(color,type)
super(color, type);
;
let pen1 = new Pencil();
let pen2 = new SomePencil("red", "common");
let pen3 = new AnotherPencil("green");
console.log("type" in pen3); // true
javascript oop
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
1
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
pen3.type !== undefined
– Keith
Nov 13 '18 at 16:23
pen3has a propertytypebecauseSomePencilhas atypebut that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?
– Mark Meyer
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Fix it by callingconst pen3 = new AnotherPencil("green", "common");
– Bergi
Nov 13 '18 at 17:26
|
show 1 more comment
2
2
2
1
Have some problem with inheritance. How to implement type inheritance from Some Pencil to Another Pencil? Need: pen3.type // common
class Pencil
constructor(color)
this.color = color;
intro()
console.log(`this is $this.color pencil`);
;
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type;
;
class AnotherPencil extends SomePencil
constructor(color,type)
super(color, type);
;
let pen1 = new Pencil();
let pen2 = new SomePencil("red", "common");
let pen3 = new AnotherPencil("green");
console.log("type" in pen3); // true
javascript oop
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
Have some problem with inheritance. How to implement type inheritance from Some Pencil to Another Pencil? Need: pen3.type // common
class Pencil
constructor(color)
this.color = color;
intro()
console.log(`this is $this.color pencil`);
;
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type;
;
class AnotherPencil extends SomePencil
constructor(color,type)
super(color, type);
;
let pen1 = new Pencil();
let pen2 = new SomePencil("red", "common");
let pen3 = new AnotherPencil("green");
console.log("type" in pen3); // true
javascript oop
javascript oop
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
asked Nov 13 '18 at 16:09
disco_dinosaurdisco_dinosaur
164
164
1
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
pen3.type !== undefined
– Keith
Nov 13 '18 at 16:23
pen3has a propertytypebecauseSomePencilhas atypebut that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?
– Mark Meyer
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Fix it by callingconst pen3 = new AnotherPencil("green", "common");
– Bergi
Nov 13 '18 at 17:26
|
show 1 more comment
1
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
pen3.type !== undefined
– Keith
Nov 13 '18 at 16:23
pen3has a propertytypebecauseSomePencilhas atypebut that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?
– Mark Meyer
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Fix it by callingconst pen3 = new AnotherPencil("green", "common");
– Bergi
Nov 13 '18 at 17:26
1
1
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
pen3.type !== undefined– Keith
Nov 13 '18 at 16:23
pen3.type !== undefined– Keith
Nov 13 '18 at 16:23
pen3 has a property type because SomePencil has a type but that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?– Mark Meyer
Nov 13 '18 at 16:27
pen3 has a property type because SomePencil has a type but that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?– Mark Meyer
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Fix it by calling
const pen3 = new AnotherPencil("green", "common");– Bergi
Nov 13 '18 at 17:26
Fix it by calling
const pen3 = new AnotherPencil("green", "common");– Bergi
Nov 13 '18 at 17:26
|
show 1 more comment
1 Answer
1
active
oldest
votes
1
Inheritance will only inherit properties and not values unless they are set in the class definition itself. For example
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type
;
new way to set defaults
class SomePencil extends Pencil
constructor(color, type = 'common')
super(color);
this.type = type;
;
Refer jsfiddle
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
1
Inheritance will only inherit properties and not values unless they are set in the class definition itself. For example
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type
;
new way to set defaults
class SomePencil extends Pencil
constructor(color, type = 'common')
super(color);
this.type = type;
;
Refer jsfiddle
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
add a comment |
1
Inheritance will only inherit properties and not values unless they are set in the class definition itself. For example
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type
;
new way to set defaults
class SomePencil extends Pencil
constructor(color, type = 'common')
super(color);
this.type = type;
;
Refer jsfiddle
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
add a comment |
1
1
1
Inheritance will only inherit properties and not values unless they are set in the class definition itself. For example
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type
;
new way to set defaults
class SomePencil extends Pencil
constructor(color, type = 'common')
super(color);
this.type = type;
;
Refer jsfiddle
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
Inheritance will only inherit properties and not values unless they are set in the class definition itself. For example
class SomePencil extends Pencil
constructor(color, type)
super(color);
this.type = type
;
new way to set defaults
class SomePencil extends Pencil
constructor(color, type = 'common')
super(color);
this.type = type;
;
Refer jsfiddle
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
answered Nov 13 '18 at 16:21
AbhidevAbhidev
4,40651525
4,40651525
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
add a comment |
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
thank you! I must be more attentive
– disco_dinosaur
Nov 13 '18 at 18:54
add a comment |
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1
I'm not clear what you need. Do you want all instances of AnotherPencil to have type="common"?
– Nicholas Tower
Nov 13 '18 at 16:17
pen3.type !== undefined– Keith
Nov 13 '18 at 16:23
pen3has a propertytypebecauseSomePencilhas atypebut that type is undefined because it hasn't been set with a value when the constructor is called. This is the way it's supposed to work. What do you want the result to be?– Mark Meyer
Nov 13 '18 at 16:27
Remember to always favor Composition over inheritance
– David Lemon
Nov 13 '18 at 16:27
Fix it by calling
const pen3 = new AnotherPencil("green", "common");– Bergi
Nov 13 '18 at 17:26