Originally posted by: SystemAdmin

Howdy,

is there a neat way to convert a string to an integer (or float).
The main job will be to decide if the string corresponds
to an integer. There is the parseInt() function that returns
NaN in case that the string does not represent a valid integer.

But it is not obvious how this can be checked

execute
{ s = 
"123" t = 
"H235" writeln( s ,
"-->",parseInt(s)); writeln( t ,
"-->",parseInt(t)); 

if(parseInt(t) == NaN) writeln(
"NO Int") 
}

yield to

123-->123 H235-->NaN

which is cossistent with the doc.

The NaN value is contagious, and a numeric operation involving NaN always returns NaN. A comparison operation involving NaN always returns 

false — even the NaN == NaN comparison.

A construction like

if(!(parseInt(t) < 0 ||  parseInt(t) >= 0)) writeln(
"NO Int")

works - but it looks weird to me. There must be easier ways to do so.,

Any ideas or hints?

Regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

what about

writeln( s ,"-->",Opl.intValue(s));
writeln( t ,"-->",Opl.intValue(t));

which will give you

123-->123
*** ERROR[GENERATE_113] : Not an integer value "H235".

?
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

Alex,

the problem with that approach is that it raises an
exception and execution is stopped.
I want to keep control in OPL script, e.g.,
if the string is a parameter, generate a warning and
switch to some default setting (or alike)

Regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi

Then you can try

execute{
  s = "123"
  t = "H235"
  
  var defaultValue=-10;
  
  s2=parseInt(s);
  t2=parseInt(t);
  
  if (s2!=s2) s2=defaultValue;
  if (t2!=t2) t2=defaultValue;
  
  writeln( s ,"-->",s2);
  writeln( t ,"-->",t2);
  
  
}

which gives

123-->123
H235-->-10

Alex
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

Alex,

thanks - the construction

if (s2!=s2) s2=defaultValue;

looks weird as well, but it seems to be better
than what I posted.

Is there a neat way to reject

s = "12xx3"

as a valid integer? (parseInt() gives 12)

Regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer

Hi,

to reject 12xx3 you can write a loop on the string and check that all characters are figures.

The loop would look a bit like

execute{
  s = "hello"
  for(var i=0;i<=s.length-1;i++) write(s.charAt(i),"-");
}

that gives

h-e-l-l-o-

Regards
#DecisionOptimization
#OPLusingCPLEXOptimizer

Originally posted by: SystemAdmin

Alex,

obviously this can be done by checking char by char.
But this is far away from being neat.
What I learned is that there is no compact way to do so.

Thanks for all the feedback.

Best regards
Norbert
#DecisionOptimization
#OPLusingCPLEXOptimizer