When to use If-else if-else over switch statements and vice versa

Question

Why you would want to use a switch block over a series of if statements   switch statements seem to do the same thing but take longer to type

User · Answer

The tendency to avoid stuff because it takes longer to type is a bad thing, try to root it out. That said, overly verbose things are also difficult to read, so small and simple is important, but it's readability not writability that's important. Concise one-liners can often be more difficult to read than a simple well laid out 3 or 4 lines.

Use whichever construct best descibes the logic of the operation.

User · Answer

The tendency to avoid stuff because it takes longer to type is a bad thing, try to root it out. That said, overly verbose things are also difficult to read, so small and simple is important, but it's readability not writability that's important. Concise one-liners can often be more difficult to read than a simple well laid out 3 or 4 lines.

Use whichever construct best descibes the logic of the operation.

User · Answer

If you are switching on the value of a single variable then I d use a switch every time  it s what the construct was made for   Otherwise  stick with multiple if-else statements

User · Answer

This depends very much on the specific case  Preferably  I think one should use the switch over the if-else if there are many nested if-elses    The question is how much is many   Yesterday I was asking myself the same question   public enum ProgramType       NEW  OLD    if  progType    OLD                 else if  progType    NEW                  if  progType    OLD                 else                 switch  progType    case OLD                 break  case NEW                 break  default      break      In this case  the 1st if has an unnecessary second test  The 2nd feels a little bad because it hides the NEW   I ended up choosing the switch because it just reads better

User · Answer

concerning Readability   I typically prefer if else constructs over switch statements  especially in languages that allows fall-through cases  What I ve found  often  is as the projects age  and multiple developers gets involved  you ll start having trouble with the construction of a switch statement     If they  the statements  become anything more than simple  many programmers become lazy and instead of reading the entire statement to understand it  they ll simply pop in a case to cover whatever case they re adding into the statement     I ve seen many cases where code repeats in a switch statement because a person s test was already covered  a simple fall-though case would have sufficed  but laziness forced them to add the redundant code at the end instead of trying to understand the switch  I ve also seen some nightmarish switch statements with many cases that were poorly constructed  and simply trying to follow all the logic  with many fall-through cases dispersed throughout  and many cases which weren t  becomes difficult     which kind of leads to the first redundancy problem I talked about     Theoretically  the same problem could exist with if else constructs  but in practice this just doesn t seem to happen as often  Maybe  just a guess  programmers are forced to read a bit more carefully because you need to understand the  often  more complex conditions being tested within the if else construct  If you re writing something simple that you know others are likely to never touch  and you can construct it well  then I guess it s a toss-up  In that case  whatever is more readable and feels best to you is probably the right answer because you re likely to be sustaining that code   concerning Speed   Switch statements often perform faster than if-else constructs  but not always   Since the possible values of a switch statement are laid out beforehand  compilers are able to optimize performance by constructing jump tables  Each condition doesn t have to be tested as in an if else construct  well  until you find the right one  anyway      However this isn t always the case  though  If you have a simple switch  say  with possible values of 1 to 10  this will be the case  The more values you add requires the jump tables to be larger and the switch becomes less efficient  not than an if else  but less efficient than the comparatively simple switch statement   Also  if the values are highly variant   i e  instead of 1 to 10  you have 10 possible values of  say  1  1000  10000  100000  and so on to 100000000000   the switch is less efficient than in the simpler case   Hope this helps

User · Answer

If you are switching on the value of a single variable then I d use a switch every time  it s what the construct was made for   Otherwise  stick with multiple if-else statements

User · Answer

As with most things you should pick which to use based on the context and what is conceptually the correct way to go   A switch is really saying  pick one of these based on this variables value  but an if statement is just a series of boolean checks   As an example  if you were doing   int value      some value if  value    1        doThis      else if  value    2        doThat      else       doTheOther        This would be much better represented as a switch as it then makes it immediately obviously that the choice of action is occurring based on the value of  value  and not some arbitrary test   Also  if you find yourself writing switches and if-elses and using an OO language you should be considering getting rid of them and using polymorphism to achieve the same result if possible   Finally  regarding switch taking longer to type  I can t remember who said it but I did once read someone ask  is your typing speed really the thing that affects how quickly you code    paraphrased

User · Answer

Use switch every time you have more than 2 conditions on a single variable  take weekdays for example  if you have a different action for every weekday you should use a switch   Other situations  multiple variables or complex if clauses you should Ifs  but there isn t a rule on where to use each

User · Answer

Switch statements are far easier to read and maintain  hands down  And are usually faster and less error prone

User · Answer

This depends very much on the specific case  Preferably  I think one should use the switch over the if-else if there are many nested if-elses    The question is how much is many   Yesterday I was asking myself the same question   public enum ProgramType       NEW  OLD    if  progType    OLD                 else if  progType    NEW                  if  progType    OLD                 else                 switch  progType    case OLD                 break  case NEW                 break  default      break      In this case  the 1st if has an unnecessary second test  The 2nd feels a little bad because it hides the NEW   I ended up choosing the switch because it just reads better

User · Answer

I have often thought that using elseif and dropping through case instances  where the language permits  are code odours  if not smells   For myself  I have normally found that nested  if then else s usually reflect things better than elseifs  and that for mutually exclusive cases  often where one combination of attributes takes precedence over another   case or something similar is clearer to read two years later   I think the select statement used by Rexx is a particularly good example of how to do  Case  well  no drop-throughs   silly example    Select     When  Vehicle      Car   Then         Name    Red Bus      When  Colour     Red   Then         Name    Ferrari      Otherwise         Name    Plain old other car      End   Oh  and if the optimisation isn t up to it  get a new compiler or language

User · Answer

Switch statements are far easier to read and maintain  hands down  And are usually faster and less error prone

User · Answer

As with most things you should pick which to use based on the context and what is conceptually the correct way to go   A switch is really saying  pick one of these based on this variables value  but an if statement is just a series of boolean checks   As an example  if you were doing   int value      some value if  value    1        doThis      else if  value    2        doThat      else       doTheOther        This would be much better represented as a switch as it then makes it immediately obviously that the choice of action is occurring based on the value of  value  and not some arbitrary test   Also  if you find yourself writing switches and if-elses and using an OO language you should be considering getting rid of them and using polymorphism to achieve the same result if possible   Finally  regarding switch taking longer to type  I can t remember who said it but I did once read someone ask  is your typing speed really the thing that affects how quickly you code    paraphrased

User · Answer

Use switch every time you have more than 2 conditions on a single variable  take weekdays for example  if you have a different action for every weekday you should use a switch   Other situations  multiple variables or complex if clauses you should Ifs  but there isn t a rule on where to use each

User · Answer

The tendency to avoid stuff because it takes longer to type is a bad thing, try to root it out. That said, overly verbose things are also difficult to read, so small and simple is important, but it's readability not writability that's important. Concise one-liners can often be more difficult to read than a simple well laid out 3 or 4 lines.

Use whichever construct best descibes the logic of the operation.

User · Answer

I personally prefer to see switch statements over too many nested if-elses because they can be much easier to read   Switches are also better in readability terms for showing a state   See also the comment in this post regarding pacman ifs

User · Answer

Let s say you have decided to use switch as you are only working on a single variable which can have different values  If this would result in a small switch statement  2-3 cases   I d say that is fine  If it seems you will end up with more I would recommend using polymorphism instead  An AbstractFactory pattern could be used here to create an object that would perform whatever action you were trying to do in the switches  The ugly switch statement will be abstracted away and you end up with cleaner code

User · Answer

concerning Readability   I typically prefer if else constructs over switch statements  especially in languages that allows fall-through cases  What I ve found  often  is as the projects age  and multiple developers gets involved  you ll start having trouble with the construction of a switch statement     If they  the statements  become anything more than simple  many programmers become lazy and instead of reading the entire statement to understand it  they ll simply pop in a case to cover whatever case they re adding into the statement     I ve seen many cases where code repeats in a switch statement because a person s test was already covered  a simple fall-though case would have sufficed  but laziness forced them to add the redundant code at the end instead of trying to understand the switch  I ve also seen some nightmarish switch statements with many cases that were poorly constructed  and simply trying to follow all the logic  with many fall-through cases dispersed throughout  and many cases which weren t  becomes difficult     which kind of leads to the first redundancy problem I talked about     Theoretically  the same problem could exist with if else constructs  but in practice this just doesn t seem to happen as often  Maybe  just a guess  programmers are forced to read a bit more carefully because you need to understand the  often  more complex conditions being tested within the if else construct  If you re writing something simple that you know others are likely to never touch  and you can construct it well  then I guess it s a toss-up  In that case  whatever is more readable and feels best to you is probably the right answer because you re likely to be sustaining that code   concerning Speed   Switch statements often perform faster than if-else constructs  but not always   Since the possible values of a switch statement are laid out beforehand  compilers are able to optimize performance by constructing jump tables  Each condition doesn t have to be tested as in an if else construct  well  until you find the right one  anyway      However this isn t always the case  though  If you have a simple switch  say  with possible values of 1 to 10  this will be the case  The more values you add requires the jump tables to be larger and the switch becomes less efficient  not than an if else  but less efficient than the comparatively simple switch statement   Also  if the values are highly variant   i e  instead of 1 to 10  you have 10 possible values of  say  1  1000  10000  100000  and so on to 100000000000   the switch is less efficient than in the simpler case   Hope this helps

User · Answer

I personally prefer to see switch statements over too many nested if-elses because they can be much easier to read   Switches are also better in readability terms for showing a state   See also the comment in this post regarding pacman ifs

User · Answer

concerning Readability   I typically prefer if else constructs over switch statements  especially in languages that allows fall-through cases  What I ve found  often  is as the projects age  and multiple developers gets involved  you ll start having trouble with the construction of a switch statement     If they  the statements  become anything more than simple  many programmers become lazy and instead of reading the entire statement to understand it  they ll simply pop in a case to cover whatever case they re adding into the statement     I ve seen many cases where code repeats in a switch statement because a person s test was already covered  a simple fall-though case would have sufficed  but laziness forced them to add the redundant code at the end instead of trying to understand the switch  I ve also seen some nightmarish switch statements with many cases that were poorly constructed  and simply trying to follow all the logic  with many fall-through cases dispersed throughout  and many cases which weren t  becomes difficult     which kind of leads to the first redundancy problem I talked about     Theoretically  the same problem could exist with if else constructs  but in practice this just doesn t seem to happen as often  Maybe  just a guess  programmers are forced to read a bit more carefully because you need to understand the  often  more complex conditions being tested within the if else construct  If you re writing something simple that you know others are likely to never touch  and you can construct it well  then I guess it s a toss-up  In that case  whatever is more readable and feels best to you is probably the right answer because you re likely to be sustaining that code   concerning Speed   Switch statements often perform faster than if-else constructs  but not always   Since the possible values of a switch statement are laid out beforehand  compilers are able to optimize performance by constructing jump tables  Each condition doesn t have to be tested as in an if else construct  well  until you find the right one  anyway      However this isn t always the case  though  If you have a simple switch  say  with possible values of 1 to 10  this will be the case  The more values you add requires the jump tables to be larger and the switch becomes less efficient  not than an if else  but less efficient than the comparatively simple switch statement   Also  if the values are highly variant   i e  instead of 1 to 10  you have 10 possible values of  say  1  1000  10000  100000  and so on to 100000000000   the switch is less efficient than in the simpler case   Hope this helps

User · Answer

Let s say you have decided to use switch as you are only working on a single variable which can have different values  If this would result in a small switch statement  2-3 cases   I d say that is fine  If it seems you will end up with more I would recommend using polymorphism instead  An AbstractFactory pattern could be used here to create an object that would perform whatever action you were trying to do in the switches  The ugly switch statement will be abstracted away and you end up with cleaner code

User · Answer

This depends very much on the specific case  Preferably  I think one should use the switch over the if-else if there are many nested if-elses    The question is how much is many   Yesterday I was asking myself the same question   public enum ProgramType       NEW  OLD    if  progType    OLD                 else if  progType    NEW                  if  progType    OLD                 else                 switch  progType    case OLD                 break  case NEW                 break  default      break      In this case  the 1st if has an unnecessary second test  The 2nd feels a little bad because it hides the NEW   I ended up choosing the switch because it just reads better

User · Answer

As with most things you should pick which to use based on the context and what is conceptually the correct way to go   A switch is really saying  pick one of these based on this variables value  but an if statement is just a series of boolean checks   As an example  if you were doing   int value      some value if  value    1        doThis      else if  value    2        doThat      else       doTheOther        This would be much better represented as a switch as it then makes it immediately obviously that the choice of action is occurring based on the value of  value  and not some arbitrary test   Also  if you find yourself writing switches and if-elses and using an OO language you should be considering getting rid of them and using polymorphism to achieve the same result if possible   Finally  regarding switch taking longer to type  I can t remember who said it but I did once read someone ask  is your typing speed really the thing that affects how quickly you code    paraphrased

User · Answer

I have often thought that using elseif and dropping through case instances  where the language permits  are code odours  if not smells   For myself  I have normally found that nested  if then else s usually reflect things better than elseifs  and that for mutually exclusive cases  often where one combination of attributes takes precedence over another   case or something similar is clearer to read two years later   I think the select statement used by Rexx is a particularly good example of how to do  Case  well  no drop-throughs   silly example    Select     When  Vehicle      Car   Then         Name    Red Bus      When  Colour     Red   Then         Name    Ferrari      Otherwise         Name    Plain old other car      End   Oh  and if the optimisation isn t up to it  get a new compiler or language

User · Answer

I have often thought that using elseif and dropping through case instances  where the language permits  are code odours  if not smells   For myself  I have normally found that nested  if then else s usually reflect things better than elseifs  and that for mutually exclusive cases  often where one combination of attributes takes precedence over another   case or something similar is clearer to read two years later   I think the select statement used by Rexx is a particularly good example of how to do  Case  well  no drop-throughs   silly example    Select     When  Vehicle      Car   Then         Name    Red Bus      When  Colour     Red   Then         Name    Ferrari      Otherwise         Name    Plain old other car      End   Oh  and if the optimisation isn t up to it  get a new compiler or language

User · Answer

I personally prefer to see switch statements over too many nested if-elses because they can be much easier to read   Switches are also better in readability terms for showing a state   See also the comment in this post regarding pacman ifs

User · Answer

Let s say you have decided to use switch as you are only working on a single variable which can have different values  If this would result in a small switch statement  2-3 cases   I d say that is fine  If it seems you will end up with more I would recommend using polymorphism instead  An AbstractFactory pattern could be used here to create an object that would perform whatever action you were trying to do in the switches  The ugly switch statement will be abstracted away and you end up with cleaner code

User · Answer

The tendency to avoid stuff because it takes longer to type is a bad thing, try to root it out. That said, overly verbose things are also difficult to read, so small and simple is important, but it's readability not writability that's important. Concise one-liners can often be more difficult to read than a simple well laid out 3 or 4 lines.

Use whichever construct best descibes the logic of the operation.

User · Answer

Use switch every time you have more than 2 conditions on a single variable  take weekdays for example  if you have a different action for every weekday you should use a switch   Other situations  multiple variables or complex if clauses you should Ifs  but there isn t a rule on where to use each

User · Answer

Let s say you have decided to use switch as you are only working on a single variable which can have different values  If this would result in a small switch statement  2-3 cases   I d say that is fine  If it seems you will end up with more I would recommend using polymorphism instead  An AbstractFactory pattern could be used here to create an object that would perform whatever action you were trying to do in the switches  The ugly switch statement will be abstracted away and you end up with cleaner code

User · Answer

If you are switching on the value of a single variable then I d use a switch every time  it s what the construct was made for   Otherwise  stick with multiple if-else statements

User · Answer

concerning Readability   I typically prefer if else constructs over switch statements  especially in languages that allows fall-through cases  What I ve found  often  is as the projects age  and multiple developers gets involved  you ll start having trouble with the construction of a switch statement     If they  the statements  become anything more than simple  many programmers become lazy and instead of reading the entire statement to understand it  they ll simply pop in a case to cover whatever case they re adding into the statement     I ve seen many cases where code repeats in a switch statement because a person s test was already covered  a simple fall-though case would have sufficed  but laziness forced them to add the redundant code at the end instead of trying to understand the switch  I ve also seen some nightmarish switch statements with many cases that were poorly constructed  and simply trying to follow all the logic  with many fall-through cases dispersed throughout  and many cases which weren t  becomes difficult     which kind of leads to the first redundancy problem I talked about     Theoretically  the same problem could exist with if else constructs  but in practice this just doesn t seem to happen as often  Maybe  just a guess  programmers are forced to read a bit more carefully because you need to understand the  often  more complex conditions being tested within the if else construct  If you re writing something simple that you know others are likely to never touch  and you can construct it well  then I guess it s a toss-up  In that case  whatever is more readable and feels best to you is probably the right answer because you re likely to be sustaining that code   concerning Speed   Switch statements often perform faster than if-else constructs  but not always   Since the possible values of a switch statement are laid out beforehand  compilers are able to optimize performance by constructing jump tables  Each condition doesn t have to be tested as in an if else construct  well  until you find the right one  anyway      However this isn t always the case  though  If you have a simple switch  say  with possible values of 1 to 10  this will be the case  The more values you add requires the jump tables to be larger and the switch becomes less efficient  not than an if else  but less efficient than the comparatively simple switch statement   Also  if the values are highly variant   i e  instead of 1 to 10  you have 10 possible values of  say  1  1000  10000  100000  and so on to 100000000000   the switch is less efficient than in the simpler case   Hope this helps

User · Answer

I personally prefer to see switch statements over too many nested if-elses because they can be much easier to read   Switches are also better in readability terms for showing a state   See also the comment in this post regarding pacman ifs

User · Answer

If you are switching on the value of a single variable then I d use a switch every time  it s what the construct was made for   Otherwise  stick with multiple if-else statements

User · Answer

Use switch every time you have more than 2 conditions on a single variable  take weekdays for example  if you have a different action for every weekday you should use a switch   Other situations  multiple variables or complex if clauses you should Ifs  but there isn t a rule on where to use each

User · Answer

This depends very much on the specific case  Preferably  I think one should use the switch over the if-else if there are many nested if-elses    The question is how much is many   Yesterday I was asking myself the same question   public enum ProgramType       NEW  OLD    if  progType    OLD                 else if  progType    NEW                  if  progType    OLD                 else                 switch  progType    case OLD                 break  case NEW                 break  default      break      In this case  the 1st if has an unnecessary second test  The 2nd feels a little bad because it hides the NEW   I ended up choosing the switch because it just reads better

User · Answer

Switch statements are far easier to read and maintain  hands down  And are usually faster and less error prone

User · Answer

I have often thought that using elseif and dropping through case instances  where the language permits  are code odours  if not smells   For myself  I have normally found that nested  if then else s usually reflect things better than elseifs  and that for mutually exclusive cases  often where one combination of attributes takes precedence over another   case or something similar is clearer to read two years later   I think the select statement used by Rexx is a particularly good example of how to do  Case  well  no drop-throughs   silly example    Select     When  Vehicle      Car   Then         Name    Red Bus      When  Colour     Red   Then         Name    Ferrari      Otherwise         Name    Plain old other car      End   Oh  and if the optimisation isn t up to it  get a new compiler or language

User · Answer

As with most things you should pick which to use based on the context and what is conceptually the correct way to go   A switch is really saying  pick one of these based on this variables value  but an if statement is just a series of boolean checks   As an example  if you were doing   int value      some value if  value    1        doThis      else if  value    2        doThat      else       doTheOther        This would be much better represented as a switch as it then makes it immediately obviously that the choice of action is occurring based on the value of  value  and not some arbitrary test   Also  if you find yourself writing switches and if-elses and using an OO language you should be considering getting rid of them and using polymorphism to achieve the same result if possible   Finally  regarding switch taking longer to type  I can t remember who said it but I did once read someone ask  is your typing speed really the thing that affects how quickly you code    paraphrased

User · Answer

Switch statements are far easier to read and maintain  hands down  And are usually faster and less error prone

[switch-statement] When to use If-else if-else over switch statements and vice versa

Examples related to switch-statement