Writing Calculator class into a "Command Line Calculator" program (Java) -

here relevant part of main program assignment:

public static void main(string [] args) {          int characters = args.length;         if (characters < 3)               system.out.println("you did not type in calculation!");          else if (characters % 2 == 0)              system.out.println("invalid number of command line parameters.");          else {              calculathor counter = new calculathor();             counter.count(args);         }     } } 

i'm allowed write class shown below (calculator) program in assignment. can't figure out how printable result calculation.

i presume switch statement working intended in receiving operator user's input , putting use need else actual result.

class calculator {  int result; int = 0;      string[] args;      void count(string[] args) {       switch (args[i].charat(i)) {     case '+': result = integer.parseint(args[i]) +     integer.parseint(args[i+2]);     break;      case '-': result = integer.parseint(args[i]) -     integer.parseint(args[i+2]);     break;     }  system.out.println("\nresult of calculation " + args[0] + " + " + args[2] + " + " + args[4] + " - " + args[6] + " " + result);      } } 

here pointers:

calculathor counter = new calculathor(); 

should be

calculator counter = new calculator(); 

and, switch statement more or less substitute if-elseif-else-statements (see linked tutorial clarification).

you want loop on each argument , check if it's number or operator. example:

for(string arg: args){     ///code  } 

or

for(int = 0; < args.length; i++) {     //code } 

within loop can have switch statement checks if current arg int or operator. could, example, increment i more 1 one summation @ each iteration, e.g i+=3 instead of i++ (warning: think through don't arrayindexoutofboundsexception)

also, there's no need charat since each arg string of length 1 (i assume). if have 1 big string want loop on args[0].