Switch command syntax?

[SteelAce]

Sorry being so fool, but I cannot find switch command syntax in https://www.mql5.com/en/docs. When I write code

 ENUM_TIMEFRAMES SetPeriodName (string period){
  switch(period)
     {
      case "M1"     : return(PERIOD_M1);
      case "M2"     : return(PERIOD_M2);

      ...

      case "Daily"  : return(PERIOD_D1);
      case "Weekly" : return(PERIOD_W1);
      case "Monthly": return(PERIOD_MN1);
      default  : Print("  cannot set period")
      }

   }

compiler shows error 'period' illegal switch expression type

I don't belive my eyes. Is it indeed restricted using string variables in switch cases or is it something else? I want to convert string values to corresponding timeframe values.

[SteelAce]

Really I have found way to go around that problem but it is still interesting why switch don't eat string variables.

[Biantoro Kunarto]

This link will show you the switch syntax : https://www.mql5.com/en/docs/basis/operators/switch, I think your problem is :

Switch Operator

Compares the expression value with constants in all the case variants and passes control to the operator that corresponds to the expression value. Each variant of case can be marked with an integer constant, a literal constant or a constant expression. The constant expression can't contain variables or function calls. Expression of the switch operator must be of integer type. 

You can't use string type for switch operator.

[Biantoro Kunarto]

You can use "if" instead of "switch"

[Stuart Browne]

As said above, switch expression must be integer. (kind of strange that the example uses string). Just use ifs

[Alain Verleyen]

Filter:
As said above, switch expression must be integer. (kind of strange that the example uses string). Just use ifs

The example use character constants not string.

[Stuart Browne]

angevoyageur:
The example use character constants not string.

Good point!

[William Roeder]

ENUM_TIMEFRAMES SetPeriodName (string period){

Where is this string coming from? Instead, make it an input, no conversion required.

input ENUM_TIMEFRAMES inpPeriod=PERIOD_CURRENT;
      ENUM_TIMEFRAMES period; // Actual
⋮
int OnInit(){
   period = inpPeriod == PERIOD_CURRENT ? ENUM_TIMEFRAMES(_Period) : period;