Getting Sum of a Class Attribute (of type integer) In all Instances
Say that I have a class as such:
class Test
var Test_Value: Int
init?(Detail_Test_Value: Int)
self.Test_Value = Detail_Test_Value
Test_Value is an integer class attribute. Say I have many instances of the class Test, all with unique values of Test_Value. What I aim to do is to obtain the sum of Test_Value from all of the instances. What are potential ways of doing this?
swift
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
add a comment |
Say that I have a class as such:
class Test
var Test_Value: Int
init?(Detail_Test_Value: Int)
self.Test_Value = Detail_Test_Value
Test_Value is an integer class attribute. Say I have many instances of the class Test, all with unique values of Test_Value. What I aim to do is to obtain the sum of Test_Value from all of the instances. What are potential ways of doing this?
swift
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
add a comment |
Say that I have a class as such:
class Test
var Test_Value: Int
init?(Detail_Test_Value: Int)
self.Test_Value = Detail_Test_Value
Test_Value is an integer class attribute. Say I have many instances of the class Test, all with unique values of Test_Value. What I aim to do is to obtain the sum of Test_Value from all of the instances. What are potential ways of doing this?
swift
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
Say that I have a class as such:
class Test
var Test_Value: Int
init?(Detail_Test_Value: Int)
self.Test_Value = Detail_Test_Value
Test_Value is an integer class attribute. Say I have many instances of the class Test, all with unique values of Test_Value. What I aim to do is to obtain the sum of Test_Value from all of the instances. What are potential ways of doing this?
swift
swift
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
edited Nov 12 '18 at 5:06
rmaddy
239k27311376
239k27311376
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
asked Nov 12 '18 at 4:37
Lucas WLucas W
288
288
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
There is no magical "all instances of a class that I've created" function in Swift that I am aware of.
In order to sum up the values of all of your Test instances you need a way to track them all. You could add a class variable to hold an array of all of them, but you'd have to deal with the fact that that would cause them to all be held strongly and could cause a memory leak.
Edit:
See this link for various ways to manage an array of weak references: https://marcosantadev.com/swift-arrays-holding-elements-weak-references/
(I suggest the WeakRef approach at the end.)
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
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
There is no magical "all instances of a class that I've created" function in Swift that I am aware of.
In order to sum up the values of all of your Test instances you need a way to track them all. You could add a class variable to hold an array of all of them, but you'd have to deal with the fact that that would cause them to all be held strongly and could cause a memory leak.
Edit:
See this link for various ways to manage an array of weak references: https://marcosantadev.com/swift-arrays-holding-elements-weak-references/
(I suggest the WeakRef approach at the end.)
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
add a comment |
There is no magical "all instances of a class that I've created" function in Swift that I am aware of.
In order to sum up the values of all of your Test instances you need a way to track them all. You could add a class variable to hold an array of all of them, but you'd have to deal with the fact that that would cause them to all be held strongly and could cause a memory leak.
Edit:
See this link for various ways to manage an array of weak references: https://marcosantadev.com/swift-arrays-holding-elements-weak-references/
(I suggest the WeakRef approach at the end.)
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
add a comment |
There is no magical "all instances of a class that I've created" function in Swift that I am aware of.
In order to sum up the values of all of your Test instances you need a way to track them all. You could add a class variable to hold an array of all of them, but you'd have to deal with the fact that that would cause them to all be held strongly and could cause a memory leak.
Edit:
See this link for various ways to manage an array of weak references: https://marcosantadev.com/swift-arrays-holding-elements-weak-references/
(I suggest the WeakRef approach at the end.)
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
There is no magical "all instances of a class that I've created" function in Swift that I am aware of.
In order to sum up the values of all of your Test instances you need a way to track them all. You could add a class variable to hold an array of all of them, but you'd have to deal with the fact that that would cause them to all be held strongly and could cause a memory leak.
Edit:
See this link for various ways to manage an array of weak references: https://marcosantadev.com/swift-arrays-holding-elements-weak-references/
(I suggest the WeakRef approach at the end.)
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
answered Nov 12 '18 at 4:41
Duncan CDuncan C
92.2k13114196
92.2k13114196
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
add a comment |
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
XCode has a memory debugger, which lists all instances(addresses) of a class at runtime. I am wondering how is XCode doing it? When we enable memory debugger, the debugging gets paused, so I guess at that moment Memory Debugger starts looking up memory addresses. The question is how are they doing it?
– Puneet Sharma
Nov 12 '18 at 6:50
add a comment |
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