Flutter: Difference in initializing variables in a Class
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2
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Currently I'm assigning all variables through initState however I'm seeing that there is no need to assign the variables through initState as I can just assign the variable with a value directly. What is the order of these assignments and how are they different? Why and when would you choose one instead of the other?
class Person {
String name = "John";
@override
void initState(){
....
....
}
}
vs
class Person {
String name;
@override
void initState(){
name = "John";
}
}
class oop
dart 
flutter asked Nov 20 at 0:10
ZeroNine
129313
add a comment |
up vote
2
down vote
favorite
Currently I'm assigning all variables through initState however I'm seeing that there is no need to assign the variables through initState as I can just assign the variable with a value directly. What is the order of these assignments and how are they different? Why and when would you choose one instead of the other?
class Person {
String name = "John";
@override
void initState(){
....
....
}
}
vs
class Person {
String name;
@override
void initState(){
name = "John";
}
}
class oop
dart flutter asked Nov 20 at 0:10
ZeroNine
129313
add a comment |
up vote
2
down vote
favorite
up vote
2
down vote
favorite
Currently I'm assigning all variables through initState however I'm seeing that there is no need to assign the variables through initState as I can just assign the variable with a value directly. What is the order of these assignments and how are they different? Why and when would you choose one instead of the other?
class Person {
String name = "John";
@override
void initState(){
....
....
}
}
vs
class Person {
String name;
@override
void initState(){
name = "John";
}
}
class oop
dart flutter asked Nov 20 at 0:10
ZeroNine
129313
Currently I'm assigning all variables through initState however I'm seeing that there is no need to assign the variables through initState as I can just assign the variable with a value directly. What is the order of these assignments and how are they different? Why and when would you choose one instead of the other?
class Person {
String name = "John";
@override
void initState(){
....
....
}
}
vs
class Person {
String name;
@override
void initState(){
name = "John";
}
}
class oop
dart flutter class oop
dart flutter asked Nov 20 at 0:10
ZeroNine
129313
asked Nov 20 at 0:10
ZeroNine
129313
asked Nov 20 at 0:10
ZeroNine
129313
asked Nov 20 at 0:10
ZeroNine
129313
asked Nov 20 at 0:10
ZeroNine
129313
129313
add a comment |
add a comment |
2 Answers
2
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1
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In your first example, the assignment takes place during construction. You might want to use this form if name is final.
In the second example, the assignment takes place when initState is called, which could be zero, one or more times. Presumably you are referring to the initState of State<T> which the framework calls once, after construction.
answered Nov 20 at 2:52
Richard Heap
4,9792313
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up vote
1
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The difference is that the first variable cannot be assigned dynamic content to, like AnimationController(vsync: this), you have to do that in initState.
I would guess initState assigning decreases performance a little bit, because you have more options.
I'd recommend using the regular assigning of variables whenever it's possible, and using initState() only when you have to.
answered Nov 20 at 6:33
01leo
278111
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
up vote
1
down vote
In your first example, the assignment takes place during construction. You might want to use this form if name is final.
In the second example, the assignment takes place when initState is called, which could be zero, one or more times. Presumably you are referring to the initState of State<T> which the framework calls once, after construction.
answered Nov 20 at 2:52
Richard Heap
4,9792313
add a comment |
up vote
1
down vote
In your first example, the assignment takes place during construction. You might want to use this form if name is final.
In the second example, the assignment takes place when initState is called, which could be zero, one or more times. Presumably you are referring to the initState of State<T> which the framework calls once, after construction.
answered Nov 20 at 2:52
Richard Heap
4,9792313
add a comment |
up vote
1
down vote
up vote
1
down vote
In your first example, the assignment takes place during construction. You might want to use this form if name is final.
In the second example, the assignment takes place when initState is called, which could be zero, one or more times. Presumably you are referring to the initState of State<T> which the framework calls once, after construction.
answered Nov 20 at 2:52
Richard Heap
4,9792313
In your first example, the assignment takes place during construction. You might want to use this form if name is final.
In the second example, the assignment takes place when initState is called, which could be zero, one or more times. Presumably you are referring to the initState of State<T> which the framework calls once, after construction.
answered Nov 20 at 2:52
Richard Heap
4,9792313
answered Nov 20 at 2:52
Richard Heap
4,9792313
answered Nov 20 at 2:52
Richard Heap
4,9792313
answered Nov 20 at 2:52
Richard Heap
4,9792313
4,9792313
add a comment |
add a comment |
up vote
1
down vote
The difference is that the first variable cannot be assigned dynamic content to, like AnimationController(vsync: this), you have to do that in initState.
I would guess initState assigning decreases performance a little bit, because you have more options.
I'd recommend using the regular assigning of variables whenever it's possible, and using initState() only when you have to.
answered Nov 20 at 6:33
01leo
278111
add a comment |
up vote
1
down vote
The difference is that the first variable cannot be assigned dynamic content to, like AnimationController(vsync: this), you have to do that in initState.
I would guess initState assigning decreases performance a little bit, because you have more options.
I'd recommend using the regular assigning of variables whenever it's possible, and using initState() only when you have to.
answered Nov 20 at 6:33
01leo
278111
add a comment |
up vote
1
down vote
up vote
1
down vote
The difference is that the first variable cannot be assigned dynamic content to, like AnimationController(vsync: this), you have to do that in initState.
I would guess initState assigning decreases performance a little bit, because you have more options.
I'd recommend using the regular assigning of variables whenever it's possible, and using initState() only when you have to.
answered Nov 20 at 6:33
01leo
278111
The difference is that the first variable cannot be assigned dynamic content to, like AnimationController(vsync: this), you have to do that in initState.
I would guess initState assigning decreases performance a little bit, because you have more options.
I'd recommend using the regular assigning of variables whenever it's possible, and using initState() only when you have to.
answered Nov 20 at 6:33
01leo
278111
answered Nov 20 at 6:33
01leo
278111
answered Nov 20 at 6:33
01leo
278111
answered Nov 20 at 6:33
01leo
278111
278111
add a comment |
add a comment |
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