Best way to format if statement with multiple conditions

Question

If you want to some code to execute based on two or more conditions which is the best way to format that if statement    first example -  if ConditionOne  amp  amp  ConditionTwo  amp  amp  ConditionThree       Code to execute     Second example -  if ConditionOne       if ConditionTwo             if ConditionThree                Code to execute                 which is easiest to understand and read bearing in mind that each condition may be a long function name or something

User · Answer

The first example is more  easy to read     Actually  in my opinion you should only use the second one whenever you have to add some  else logic   but for a simple Conditional  use the first flavor  If you are worried about the long of the condition you always can use the next syntax   if ConditionOneThatIsTooLongAndProbablyWillUseAlmostOneLine                   amp  amp  ConditionTwoThatIsLongAsWell                   amp  amp  ConditionThreeThatAlsoIsLong            Code to execute      Good Luck

User · Answer

In Perl you could do this        VeryLongCondition 1   or last      VeryLongCondition 2   or last      VeryLongCondition 3   or last      VeryLongCondition 4   or last      VeryLongCondition 5   or last      VeryLongCondition 6   or last       Guarded code goes here    If any of the conditions fail it will just continue on  after the block  If you are defining any variables that you want to keep around after the block  you will need to define them before the block

User · Answer

The question was asked and has  so far  been answered as though the decision should be made purely on  syntactic  grounds    I would say that the right answer of how you lay-out a number of conditions within an if  ought to depend on  semantics  too  So conditions should be broken up and grouped according to what things go together  conceptually    If two tests are really two sides of the same coin eg  if  x 0   amp  amp   x lt  100  then put them together on the same line  If another condition is conceptually far more distant eg   user hasPermission Admin    then put it on it s own line  Eg   if user hasPermission Admin         if  x  gt   0   amp  amp   x  lt  100             do something

User · Answer

I ve been facing this dilemma for a long time and I still can t find a proper solution  In my opinion only good way is to first try to get rid of conditions before so you re not suddenly comparing 5 of them   If there s no alternative then like others have suggested - break it down into separete ones and shorten the names or group them and e g  if all must be true then use something like  if no false in array of x then run    If all fails  Eoin Campbell gave pretty good ideas

User · Answer

The first example is more  easy to read     Actually  in my opinion you should only use the second one whenever you have to add some  else logic   but for a simple Conditional  use the first flavor  If you are worried about the long of the condition you always can use the next syntax   if ConditionOneThatIsTooLongAndProbablyWillUseAlmostOneLine                   amp  amp  ConditionTwoThatIsLongAsWell                   amp  amp  ConditionThreeThatAlsoIsLong            Code to execute      Good Luck

User · Answer

if       single conditional expression A        amp  amp    single conditional expression B        amp  amp    single conditional expression C             opAllABC      else      opNoneABC        Formatting a multiple conditional expressions in an if-else statement this way    allows for enhanced readability  a  all binary logical operations   amp  amp       in the expression shown first b  both conditional operands of each binary operation are obvious because they align vertically c  nested logical expressions operations are made obvious using indentation  just like nesting statements inside clause requires explicit parenthesis  not rely on operator precedence rules  a  this avoids a common static analysis errors allows for easier debugging a  disable individual single conditional tests with just a    b  set a break point just before or after any individual test c  e g           disable any single conditional test with just a pre-pended         set a break point before any individual test    syntax   1  amp  amp   and   0     usually never creates any real code if     1      amp  amp    single conditional expression A        amp  amp    single conditional expression B        amp  amp      0              single conditional expression C                single conditional expression D                               else

User · Answer

The question was asked and has  so far  been answered as though the decision should be made purely on  syntactic  grounds    I would say that the right answer of how you lay-out a number of conditions within an if  ought to depend on  semantics  too  So conditions should be broken up and grouped according to what things go together  conceptually    If two tests are really two sides of the same coin eg  if  x 0   amp  amp   x lt  100  then put them together on the same line  If another condition is conceptually far more distant eg   user hasPermission Admin    then put it on it s own line  Eg   if user hasPermission Admin         if  x  gt   0   amp  amp   x  lt  100             do something

User · Answer

The first one is easier  because  if you read it left to right you get   If something AND somethingelse AND somethingelse THEN    which is an easy to understand sentence  The second example reads  If something THEN if somethingelse THEN if something else THEN   which is clumsy   Also  consider if you wanted to use some ORs in your clause - how would you do that in the second style

User · Answer

The second one is a classic example of the Arrow Anti-pattern So I d avoid it     If your conditions are too long extract them into methods properties

User · Answer

I ve been facing this dilemma for a long time and I still can t find a proper solution  In my opinion only good way is to first try to get rid of conditions before so you re not suddenly comparing 5 of them   If there s no alternative then like others have suggested - break it down into separete ones and shorten the names or group them and e g  if all must be true then use something like  if no false in array of x then run    If all fails  Eoin Campbell gave pretty good ideas

User · Answer

Other answers explain why the first option is normally the best  But if you have multiple conditions  consider creating a separate function  or property  doing the condition checks in option 1  This makes the code much easier to read  at least when you use good method names   if MyChecksAreOk      Code to execute         private bool MyChecksAreOk          return ConditionOne  amp  amp  ConditionTwo  amp  amp  ConditionThree      It the conditions only rely on local scope variables  you could make the new function static and pass in everything you need  If there is a mix  pass in the local stuff

User · Answer

In Perl you could do this        VeryLongCondition 1   or last      VeryLongCondition 2   or last      VeryLongCondition 3   or last      VeryLongCondition 4   or last      VeryLongCondition 5   or last      VeryLongCondition 6   or last       Guarded code goes here    If any of the conditions fail it will just continue on  after the block  If you are defining any variables that you want to keep around after the block  you will need to define them before the block

User · Answer

The first one is easier  because  if you read it left to right you get   If something AND somethingelse AND somethingelse THEN    which is an easy to understand sentence  The second example reads  If something THEN if somethingelse THEN if something else THEN   which is clumsy   Also  consider if you wanted to use some ORs in your clause - how would you do that in the second style

User · Answer

When condition is really complex I use the following style  PHP real life example    if   format bool  amp  amp                  isset   column info  native type                  amp  amp  stripos   column info  native type     bool        false                        isset   column info  driver decl type                  amp  amp  stripos   column info  driver decl type     bool        false                        isset   column info  pdo type                  amp  amp   column info  pdo type      PDO  PARAM BOOL                     I believe it s more nice and readable than nesting multiple levels of if    And in some cases like this you simply can t break complex condition into pieces because otherwise you would have to repeat the same statements in if         block many times   I also believe that adding some  air  into code is always a good idea  It improves readability greatly

User · Answer

In Perl you could do this        VeryLongCondition 1   or last      VeryLongCondition 2   or last      VeryLongCondition 3   or last      VeryLongCondition 4   or last      VeryLongCondition 5   or last      VeryLongCondition 6   or last       Guarded code goes here    If any of the conditions fail it will just continue on  after the block  If you are defining any variables that you want to keep around after the block  you will need to define them before the block

User · Answer

The first one is easier  because  if you read it left to right you get   If something AND somethingelse AND somethingelse THEN    which is an easy to understand sentence  The second example reads  If something THEN if somethingelse THEN if something else THEN   which is clumsy   Also  consider if you wanted to use some ORs in your clause - how would you do that in the second style

User · Answer

I prefer Option A  bool a  b  c   if  a  amp  amp  b  amp  amp  c          This is neat  amp  readable     If you do have particularly long variables method conditions you can just line break them  if  VeryLongConditionMethod a   amp  amp      VeryLongConditionMethod b   amp  amp      VeryLongConditionMethod c          This is still readable     If they re even more complicated  then I d consider doing the condition methods separately outside the if statement  bool aa   FirstVeryLongConditionMethod a   amp  amp  SecondVeryLongConditionMethod a   bool bb   FirstVeryLongConditionMethod b   amp  amp  SecondVeryLongConditionMethod b   bool cc   FirstVeryLongConditionMethod c   amp  amp  SecondVeryLongConditionMethod c    if  aa  amp  amp  bb  amp  amp  cc         This is again neat  amp  readable      although you probably need to sanity check your method names        IMHO The only reason for option  B  would be if you have separate else functions to run for each condition   e g   if  a         if  b                   else                 Do Something Else B         else        Do Something Else A

User · Answer

The first example is more  easy to read     Actually  in my opinion you should only use the second one whenever you have to add some  else logic   but for a simple Conditional  use the first flavor  If you are worried about the long of the condition you always can use the next syntax   if ConditionOneThatIsTooLongAndProbablyWillUseAlmostOneLine                   amp  amp  ConditionTwoThatIsLongAsWell                   amp  amp  ConditionThreeThatAlsoIsLong            Code to execute      Good Luck

User · Answer

I prefer Option A  bool a  b  c   if  a  amp  amp  b  amp  amp  c          This is neat  amp  readable     If you do have particularly long variables method conditions you can just line break them  if  VeryLongConditionMethod a   amp  amp      VeryLongConditionMethod b   amp  amp      VeryLongConditionMethod c          This is still readable     If they re even more complicated  then I d consider doing the condition methods separately outside the if statement  bool aa   FirstVeryLongConditionMethod a   amp  amp  SecondVeryLongConditionMethod a   bool bb   FirstVeryLongConditionMethod b   amp  amp  SecondVeryLongConditionMethod b   bool cc   FirstVeryLongConditionMethod c   amp  amp  SecondVeryLongConditionMethod c    if  aa  amp  amp  bb  amp  amp  cc         This is again neat  amp  readable      although you probably need to sanity check your method names        IMHO The only reason for option  B  would be if you have separate else functions to run for each condition   e g   if  a         if  b                   else                 Do Something Else B         else        Do Something Else A

User · Answer

The first one is easier  because  if you read it left to right you get   If something AND somethingelse AND somethingelse THEN    which is an easy to understand sentence  The second example reads  If something THEN if somethingelse THEN if something else THEN   which is clumsy   Also  consider if you wanted to use some ORs in your clause - how would you do that in the second style

User · Answer

The second one is a classic example of the Arrow Anti-pattern So I d avoid it     If your conditions are too long extract them into methods properties

User · Answer

Other answers explain why the first option is normally the best  But if you have multiple conditions  consider creating a separate function  or property  doing the condition checks in option 1  This makes the code much easier to read  at least when you use good method names   if MyChecksAreOk      Code to execute         private bool MyChecksAreOk          return ConditionOne  amp  amp  ConditionTwo  amp  amp  ConditionThree      It the conditions only rely on local scope variables  you could make the new function static and pass in everything you need  If there is a mix  pass in the local stuff

User · Answer

The first example is more  easy to read     Actually  in my opinion you should only use the second one whenever you have to add some  else logic   but for a simple Conditional  use the first flavor  If you are worried about the long of the condition you always can use the next syntax   if ConditionOneThatIsTooLongAndProbablyWillUseAlmostOneLine                   amp  amp  ConditionTwoThatIsLongAsWell                   amp  amp  ConditionThreeThatAlsoIsLong            Code to execute      Good Luck

User · Answer

Other answers explain why the first option is normally the best  But if you have multiple conditions  consider creating a separate function  or property  doing the condition checks in option 1  This makes the code much easier to read  at least when you use good method names   if MyChecksAreOk      Code to execute         private bool MyChecksAreOk          return ConditionOne  amp  amp  ConditionTwo  amp  amp  ConditionThree      It the conditions only rely on local scope variables  you could make the new function static and pass in everything you need  If there is a mix  pass in the local stuff

User · Answer

In Perl you could do this        VeryLongCondition 1   or last      VeryLongCondition 2   or last      VeryLongCondition 3   or last      VeryLongCondition 4   or last      VeryLongCondition 5   or last      VeryLongCondition 6   or last       Guarded code goes here    If any of the conditions fail it will just continue on  after the block  If you are defining any variables that you want to keep around after the block  you will need to define them before the block

User · Answer

I prefer Option A  bool a  b  c   if  a  amp  amp  b  amp  amp  c          This is neat  amp  readable     If you do have particularly long variables method conditions you can just line break them  if  VeryLongConditionMethod a   amp  amp      VeryLongConditionMethod b   amp  amp      VeryLongConditionMethod c          This is still readable     If they re even more complicated  then I d consider doing the condition methods separately outside the if statement  bool aa   FirstVeryLongConditionMethod a   amp  amp  SecondVeryLongConditionMethod a   bool bb   FirstVeryLongConditionMethod b   amp  amp  SecondVeryLongConditionMethod b   bool cc   FirstVeryLongConditionMethod c   amp  amp  SecondVeryLongConditionMethod c    if  aa  amp  amp  bb  amp  amp  cc         This is again neat  amp  readable      although you probably need to sanity check your method names        IMHO The only reason for option  B  would be if you have separate else functions to run for each condition   e g   if  a         if  b                   else                 Do Something Else B         else        Do Something Else A

User · Answer

The question was asked and has  so far  been answered as though the decision should be made purely on  syntactic  grounds    I would say that the right answer of how you lay-out a number of conditions within an if  ought to depend on  semantics  too  So conditions should be broken up and grouped according to what things go together  conceptually    If two tests are really two sides of the same coin eg  if  x 0   amp  amp   x lt  100  then put them together on the same line  If another condition is conceptually far more distant eg   user hasPermission Admin    then put it on it s own line  Eg   if user hasPermission Admin         if  x  gt   0   amp  amp   x  lt  100             do something

User · Answer

The second one is a classic example of the Arrow Anti-pattern So I d avoid it     If your conditions are too long extract them into methods properties

User · Answer

if       single conditional expression A        amp  amp    single conditional expression B        amp  amp    single conditional expression C             opAllABC      else      opNoneABC        Formatting a multiple conditional expressions in an if-else statement this way    allows for enhanced readability  a  all binary logical operations   amp  amp       in the expression shown first b  both conditional operands of each binary operation are obvious because they align vertically c  nested logical expressions operations are made obvious using indentation  just like nesting statements inside clause requires explicit parenthesis  not rely on operator precedence rules  a  this avoids a common static analysis errors allows for easier debugging a  disable individual single conditional tests with just a    b  set a break point just before or after any individual test c  e g           disable any single conditional test with just a pre-pended         set a break point before any individual test    syntax   1  amp  amp   and   0     usually never creates any real code if     1      amp  amp    single conditional expression A        amp  amp    single conditional expression B        amp  amp      0              single conditional expression C                single conditional expression D                               else

User · Answer

The second one is a classic example of the Arrow Anti-pattern So I d avoid it     If your conditions are too long extract them into methods properties

User · Answer

When condition is really complex I use the following style  PHP real life example    if   format bool  amp  amp                  isset   column info  native type                  amp  amp  stripos   column info  native type     bool        false                        isset   column info  driver decl type                  amp  amp  stripos   column info  driver decl type     bool        false                        isset   column info  pdo type                  amp  amp   column info  pdo type      PDO  PARAM BOOL                     I believe it s more nice and readable than nesting multiple levels of if    And in some cases like this you simply can t break complex condition into pieces because otherwise you would have to repeat the same statements in if         block many times   I also believe that adding some  air  into code is always a good idea  It improves readability greatly

User · Answer

Other answers explain why the first option is normally the best  But if you have multiple conditions  consider creating a separate function  or property  doing the condition checks in option 1  This makes the code much easier to read  at least when you use good method names   if MyChecksAreOk      Code to execute         private bool MyChecksAreOk          return ConditionOne  amp  amp  ConditionTwo  amp  amp  ConditionThree      It the conditions only rely on local scope variables  you could make the new function static and pass in everything you need  If there is a mix  pass in the local stuff

User · Answer

I prefer Option A  bool a  b  c   if  a  amp  amp  b  amp  amp  c          This is neat  amp  readable     If you do have particularly long variables method conditions you can just line break them  if  VeryLongConditionMethod a   amp  amp      VeryLongConditionMethod b   amp  amp      VeryLongConditionMethod c          This is still readable     If they re even more complicated  then I d consider doing the condition methods separately outside the if statement  bool aa   FirstVeryLongConditionMethod a   amp  amp  SecondVeryLongConditionMethod a   bool bb   FirstVeryLongConditionMethod b   amp  amp  SecondVeryLongConditionMethod b   bool cc   FirstVeryLongConditionMethod c   amp  amp  SecondVeryLongConditionMethod c    if  aa  amp  amp  bb  amp  amp  cc         This is again neat  amp  readable      although you probably need to sanity check your method names        IMHO The only reason for option  B  would be if you have separate else functions to run for each condition   e g   if  a         if  b                   else                 Do Something Else B         else        Do Something Else A

User · Answer

The question was asked and has  so far  been answered as though the decision should be made purely on  syntactic  grounds    I would say that the right answer of how you lay-out a number of conditions within an if  ought to depend on  semantics  too  So conditions should be broken up and grouped according to what things go together  conceptually    If two tests are really two sides of the same coin eg  if  x 0   amp  amp   x lt  100  then put them together on the same line  If another condition is conceptually far more distant eg   user hasPermission Admin    then put it on it s own line  Eg   if user hasPermission Admin         if  x  gt   0   amp  amp   x  lt  100             do something

[if-statement] Best way to format if statement with multiple conditions

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