Can I use a case switch statement with two variables

Question

I am a newbie when it comes to JavaScript and it was my understanding that using one SWITCH CASE statements is faster than a whole bunch of IF statements     However  I want to use a SWITCH CASE statement with two variables   My web app has two sliders  each of which have five states   I want the behavior to be based on the states of these two variables   Obviously that is a whole heck of a lot of IF THEN statements   One way I thought about doing it was concatenating the two variables into one and then I could SWITCH CASE that   Is there a better way of accomplishing a SWITCH CASE using two variables    Thanks

User · Answer

If the action of each combination is static, you could build a two-dimensional array:

var data = [
  [1,2,3,4,5],
  [6,7,8,9,10],
  [11,12,13,14,15],
  [16,17,18,19,20],
  [21,22,23,24,25]
];

The numbers in above example can be anything, such as string, array, etc. Fetching the value is now a one-liner (assuming sliders have a value range of [0,5):

var info = data[firstSliderValue][secondSliderValue];

User · Answer

Languages like scala amp python give to you very powerful stuff like patternMatching  unfortunately this is still a missing-feature in Java    but there is a solution  which I don t like in most of the cases   you can do something like this  final int s1Value   0  final int s2Value   0  final String s1    quot a quot   final String s2    quot g quot    switch  s1   s2   s1Value   s2Value       case  quot ag00 quot   return true      default  return false

User · Answer

var var1    something   var var2    something else   switch var1         var2        case  something something else                       break      case  something               break      case                    break      If you have 5 possibilities for each one you will get 25 cases

User · Answer

Yeah  But not in a normal way  You will have to use switch as closure   ex -  function test input1  input2         switch  true            case input1  gt  input2                      console log input1     is larger than     input2                       break          case input1  lt  input2                      console log input2     is larger than     input1           default                      console log input1     is equal to     input2

User · Answer

Yes you can also do       switch  true          case  var1     true  amp  amp  var2     true             do something        break       case  var1     false  amp  amp  var2     false             do something        break         default           This will always execute the switch  pretty much just like if else but looks cleaner  Just continue checking your variables in the case expressions

User · Answer

You could give each position on each slider a different binary value from 1 to 1000000000 and then work with the sum

User · Answer

How about a bitwise operator  Instead of strings  you re dealing with  enums   which looks more  elegant       Declare slider s state  enum  var SliderOne         A  1      B  2      C  4      D  8      E  16     var SliderTwo         A  32      B  64      C  128      D  256      E  512        Set state var s1   SliderOne A      s2   SliderTwo B      Switch state switch  s1   s2        case SliderOne A   SliderTwo A       case SliderOne A   SliderTwo C              Logic when State  1 is A  and State  2 is either A or C         break      case SliderOne B   SliderTwo C              Logic when State  1 is B  and State  2 is C         break      case SliderOne E   SliderTwo E       default             Logic when State  1 is E  and State  2 is E or            none of above match         break        I however agree with others  25 cases in a switch-case logic is not too pretty  and if-else might  in some cases   look  better  Anyway

User · Answer

First  JavaScript s switch is no faster than if else  and sometimes much slower    Second  the only way to use switch with multiple variables is to combine them into one primitive  string  number  etc  value   var stateA    foo   var stateB    bar   switch  stateA    -    stateB        case  foo-bar                   But  personally  I would rather see a set of if else statements   Edit  When all the values are integers  it appears that switch can out-perform if else in Chrome  See the comments

User · Answer

I don t believe a switch case is any faster than a series of if elseif s  They do the same thing  but if elseif s you can check multiple variables  You cannot use a switch case on more than one value

[javascript] Can I use a case/switch statement with two variables?

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