Swift - dictionary with array - get reference to array [duplicate]
This question already has an answer here:
Swiftier Swift for 'add to array, or create if not there…'
1 answer
I currently have this code:
var dic = [String: [String]]()
if (dic.index(forKey: key) != nil){
dic[key]?.append(m)
}
else {
dic[key] = [m]
}
However, in dic.index(forKey: key) and dic[key]?.append(m) I calculate the key twice.
Is there a possibility to do something like this?:
var dictKeyVal = &dic[key]
if (dictKeyVal != nil) {
dictKeyVal?.append(m)
}
else {
dic[key] = [m]
}
where I get the reference to array at key or nil if there is no key
arrays swift dictionary
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
marked as duplicate by Martin R arrays
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Nov 22 '18 at 10:39
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
add a comment |
This question already has an answer here:
Swiftier Swift for 'add to array, or create if not there…'
1 answer
I currently have this code:
var dic = [String: [String]]()
if (dic.index(forKey: key) != nil){
dic[key]?.append(m)
}
else {
dic[key] = [m]
}
However, in dic.index(forKey: key) and dic[key]?.append(m) I calculate the key twice.
Is there a possibility to do something like this?:
var dictKeyVal = &dic[key]
if (dictKeyVal != nil) {
dictKeyVal?.append(m)
}
else {
dic[key] = [m]
}
where I get the reference to array at key or nil if there is no key
arrays swift dictionary
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
marked as duplicate by Martin R arrays
Users with the arrays badge can single-handedly close arrays questions as duplicates and reopen them as needed.
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Nov 22 '18 at 10:39
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
Tip: You should never do this in Swiftif (dictKeyVal != nil).
– Rakesha Shastri
Nov 22 '18 at 10:17
add a comment |
This question already has an answer here:
Swiftier Swift for 'add to array, or create if not there…'
1 answer
I currently have this code:
var dic = [String: [String]]()
if (dic.index(forKey: key) != nil){
dic[key]?.append(m)
}
else {
dic[key] = [m]
}
However, in dic.index(forKey: key) and dic[key]?.append(m) I calculate the key twice.
Is there a possibility to do something like this?:
var dictKeyVal = &dic[key]
if (dictKeyVal != nil) {
dictKeyVal?.append(m)
}
else {
dic[key] = [m]
}
where I get the reference to array at key or nil if there is no key
arrays swift dictionary
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
This question already has an answer here:
Swiftier Swift for 'add to array, or create if not there…'
1 answer
I currently have this code:
var dic = [String: [String]]()
if (dic.index(forKey: key) != nil){
dic[key]?.append(m)
}
else {
dic[key] = [m]
}
However, in dic.index(forKey: key) and dic[key]?.append(m) I calculate the key twice.
Is there a possibility to do something like this?:
var dictKeyVal = &dic[key]
if (dictKeyVal != nil) {
dictKeyVal?.append(m)
}
else {
dic[key] = [m]
}
where I get the reference to array at key or nil if there is no key
This question already has an answer here:
Swiftier Swift for 'add to array, or create if not there…'
1 answer
arrays swift dictionary
arrays swift dictionary
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
asked Nov 22 '18 at 10:04
Martin PerryMartin Perry
5,08523064
5,08523064
marked as duplicate by Martin R arrays
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Nov 22 '18 at 10:39
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
marked as duplicate by Martin R arrays
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Nov 22 '18 at 10:39
This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.
2
Tip: You should never do this in Swiftif (dictKeyVal != nil).
– Rakesha Shastri
Nov 22 '18 at 10:17
add a comment |
2
Tip: You should never do this in Swiftif (dictKeyVal != nil).
– Rakesha Shastri
Nov 22 '18 at 10:17
2
2
Tip: You should never do this in Swift
if (dictKeyVal != nil).– Rakesha Shastri
Nov 22 '18 at 10:17
Tip: You should never do this in Swift
if (dictKeyVal != nil).– Rakesha Shastri
Nov 22 '18 at 10:17
add a comment |
1 Answer
1
active
oldest
votes
You can simply use a default value for the subscript and your whole code will be simplified to this:
var dic = [String: [String]]()
dic[key, default: ].append(m)
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result indic[key] = [m,m]instead of the desireddic[key] = [m]in case there was no value forkey.
– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
add a comment |
1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You can simply use a default value for the subscript and your whole code will be simplified to this:
var dic = [String: [String]]()
dic[key, default: ].append(m)
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result indic[key] = [m,m]instead of the desireddic[key] = [m]in case there was no value forkey.
– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
add a comment |
You can simply use a default value for the subscript and your whole code will be simplified to this:
var dic = [String: [String]]()
dic[key, default: ].append(m)
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result indic[key] = [m,m]instead of the desireddic[key] = [m]in case there was no value forkey.
– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
add a comment |
You can simply use a default value for the subscript and your whole code will be simplified to this:
var dic = [String: [String]]()
dic[key, default: ].append(m)
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
You can simply use a default value for the subscript and your whole code will be simplified to this:
var dic = [String: [String]]()
dic[key, default: ].append(m)
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
answered Nov 22 '18 at 10:10
Dávid PásztorDávid Pásztor
21.4k82749
21.4k82749
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result indic[key] = [m,m]instead of the desireddic[key] = [m]in case there was no value forkey.
– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
add a comment |
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result indic[key] = [m,m]instead of the desireddic[key] = [m]in case there was no value forkey.
– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
Default should be [m]
– Joakim Danielson
Nov 22 '18 at 10:11
@JoakimDanielson nope, that would result in
dic[key] = [m,m] instead of the desired dic[key] = [m] in case there was no value for key.– Dávid Pásztor
Nov 22 '18 at 10:13
@JoakimDanielson nope, that would result in
dic[key] = [m,m] instead of the desired dic[key] = [m] in case there was no value for key.– Dávid Pásztor
Nov 22 '18 at 10:13
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
Sorry, now I get it. Neat solution btw.
– Joakim Danielson
Nov 22 '18 at 10:15
add a comment |
2
Tip: You should never do this in Swift
if (dictKeyVal != nil).– Rakesha Shastri
Nov 22 '18 at 10:17