Switch case can I use a range instead of a one number

Question

I want to use switch  but I have many cases  is there any shortcut   So far the only solution I know and tried is    switch  number    case 1  something  break  case 2  other thing  break      case 9             break      What I hope I m able to do is something like   switch  number    case  1 to 4   do the same for all of them  break  case  5 to 9   again  same thing for these numbers  break

User · Answer

A bit late to the game for this question, but in recent changes introduced in C# 7 (Available by default in Visual Studio 2017/.NET Framework 4.6.2), range-based switching is now possible with the switch statement.

Example:

int i = 63;

switch (i)
{
    case int n when (n >= 100):
        Console.WriteLine($"I am 100 or above: {n}");
        break;

    case int n when (n < 100 && n >= 50 ):
        Console.WriteLine($"I am between 99 and 50: {n}");
        break;

    case int n when (n < 50):
        Console.WriteLine($"I am less than 50: {n}");
        break;
}

Notes:

The parentheses ( and ) are not required in the when condition, but are used in this example to highlight the comparison(s).
var may also be used in lieu of int. For example: case var n when n >= 100:.

User · Answer

Here is a better and elegant solution for your problem statement   int mynumbercheck   1000     Your number to be checked var myswitch   new Dictionary  lt Func lt int bool gt   Action gt                                x   gt  x  lt  10           gt    Do this                          x   gt  x  lt  100           gt    Do this                        x   gt  x  lt  1000           gt    Do this                        x   gt  x  lt  10000          gt    Do this                        x   gt  x  lt  100000         gt    Do this                       x   gt  x  lt  1000000         gt    Do this                         Now to call our conditional switch     myswitch First sw   gt  sw Key mynumbercheck   Value      Alternate for Switch ifElse

User · Answer

Through switch case it s impossible You can go with nested if statements   if number gt  1  amp  amp  number lt  4     Do something  else if number gt  5  amp  amp  number lt  9     Do something

User · Answer

If the question was about C  you didn t say   then the answer is no  but  GCC and Clang  maybe others  support a range syntax  but it s not valid ISO C   switch  number        case 1     4             Do something          break       case 5     9             Do something else          break      Be sure to have a space before and after the     or else you ll get a syntax error

User · Answer

As mentioned if-else would be better in this case  where you will be handling a range   if number  gt   1  amp  amp  number  lt   4         do something    else if number  gt   5  amp  amp  number  lt   9         do something else

User · Answer

To complete the thread  here is the syntax with C  8      var percent   price switch         var n when n  gt   1000000   gt  7f      var n when n  gt   900000   gt  7 1f      var n when n  gt   800000   gt  7 2f          gt  0f    default value        If you want to specify the ranges      var percent2   price switch         var n when n  gt   1000000   gt  7f      var n when n  lt  1000000  amp  amp  n  gt   900000   gt  7 1f      var n when n  lt  900000  amp  amp  n  gt   800000   gt  7 2f          gt  0f    default value

User · Answer

First of all  you should specify the programming language you re referring to  Second  switch statements are properly used for closed sets of options regarding the switched variable  e g  enumerations or predefined strings  For this case  I would suggest using the good old if-else structure

User · Answer

In  Net only Visual Basic allows ranges in switch statements  but in C  there is no valid syntax for this   Tackling your specific problem in C   I would solve it thus   if number  gt   1  amp  amp  number  lt   9     Guard statement       if number  lt  5                   Case  1 to 4              break             else                  Case  5 to 9              break            else          Default code goes here        break       To illustrate this further  imagine you have a percentage value   Using your problem as a template  you might wish this to look like   switch  percentage        case  0 to 19           break       case  20 to 39           break       case  40 to 69           break       case  70 to 79           break       case  80 to 100           break       default          break       However  since C  doesn t allow that syntax  here is a solution that C  does allow   if  percentage  gt   0  amp  amp  percentage  lt   100     Guard statement       if  percentage  gt   40                if  percentage  gt   80                           Case  80  to 100                  break                     else                       if  percentage  gt   70                                   Case  70  to 79                      break                             else                                  Case  40  to 69                      break                                       else               if  percentage  gt   20                           Case  20  to 39                  break                     else                          Case  0  to 19                  break                       else          Default code goes here        break       It can take a little getting used to  but it s fine once you get it   Personally  I would welcome switch statements to allow ranges   The future of C  switch statements  Here are some ideas I had of how switch statements could be improved   Version A  switch value        case  x   gt  x  gt   1  amp  amp  x  lt   4       break       case  x   gt  x  gt   5  amp  amp  x  lt   9       break       default      break       Version B  switch param1  param2             case  param1  gt   1  amp  amp  param1  lt   4       break       case  param1  gt   5  amp  amp  param1  lt   9    param2    param1       break       default      break

User · Answer

Interval is constant    int range   5  int newNumber   number   range   switch  newNumber           case  0     number 0 to 4                 break        case  1     number 5 to 9                 break        case  2     number 10 to 14                 break        default   break       Otherwise     if else

User · Answer

You could have switch construct  handle  ranges by using it in conjunction with a List of your bounds   List lt int gt  bounds   new List lt int gt     int MinValue  0  4  9  17  20  int MaxValue     switch  bounds IndexOf bounds Last x   gt  x  lt  j          case 0      lt  0         break       case 1      gt   1 and  lt  4         break      case 2      gt   5 and  lt  9         break      case 3      gt   10 and  lt  17         break      case 4      gt   18 and  lt  20         break       case 5      gt 20         break      With this approach ranges can have different spans

User · Answer

If you use C C    there s no  range  syntax  You can only list all values after each  case  segment  Language Ada or Pascal support range syntax

User · Answer

I would use ternary operators to categorize your switch conditions   So     switch  number  gt  9    High            number  gt  5    Mid            number  gt  1    Low     Floor                           case  High                       do the thing                      break                 case  Mid                       do the other thing                      break                 case  Low                       do something else                      break                 case  Floor                       do whatever                      break

User · Answer

In C  switch cases are basically dictionaries on what to do next  Since you can t look up a range in a dictionary  the best you can do is the case     when statement Steve Gomez mentioned

User · Answer

You can use if-else statements with    operators  or-operator  like   if case1    true    case2    true    case3    true           Do this           else if case4    true    case5    true    case6    true           Do this           else if case7    true    case8    true    case9    true           Do this

User · Answer

If-else should be used in that case  But if there is still a need of switch for any reason  you can do as below  first cases without break will propagate till first break is encountered  As previous answers have suggested I recommend if-else over switch   switch  number               case 1              case 2              case 3              case 4    do something                      break              case 5              case 6              case 7              case 8              case 9    Do some other-thing                     break

[c#] Switch case: can I use a range instead of a one number

Examples related to c#

Examples related to switch-statement