Convert arithmetic string into double in Java -

i have program user inputs 6 doubles, , program outputs every combination of operators can go in-between doubles 1024 separate strings. here first 2 results if user inputed 14,17,200,1,5, , 118:

"14.0+17.0+200.0+1.0+5.0+118.0"  "14.0+17.0+200.0+1.0+5.0-118.0" 

what want perform arithmetic according order of operations. each double stored variable through f , each operator in-between these variables stored char a_b through e_f. so:

    double a, b, c, d, e, f;     char a_b, b_c, c_d, d_e, e_f; 

my first thought write code this:

    public double operategroup() {     value = 0;      switch (a_b) {     case '+':         value += + b;         break;     case '-':         value += - b;         break;     case '*':         value += * b;         break;     case '/':         value += / b;         break;     default:         break;     }      switch (b_c) {     case '+':         value += c;         break;     case '-':         value += -c;         break;     case '*':         value *= c;         break;     case '/':         value /= c;         break;     default:         break;     }      switch (c_d) {     case '+':         value += d;         break;     case '-':         value += -d;         break;     case '*':         value *= d;         break;     case '/':         value /= d;         break;     default:         break;     }      switch (d_e) {     case '+':         value += e;         break;     case '-':         value += -e;         break;     case '*':         value *= e;         break;     case '/':         value /= e;         break;     default:         break;     }      switch (e_f) {     case '+':         value += f;         break;     case '-':         value += -f;         break;     case '*':         value *= f;         break;     case '/':         value /= f;         break;     default:         break;     }      return value; } 

but doesn't work because same doing (a o b) o c) o d) o e) o arbitrary operator. tips?

if need operators' , operands' information, should build parse tree (this has been asked before).

if interested in result, can evaluate string directly:

import javax.script.scriptenginemanager; import javax.script.scriptengine; public class eval {     public static void main(string[] args) throws exception {         scriptenginemanager s = new scriptenginemanager();         scriptengine engine = s.getenginebyname("javascript");         string exp = "14.0+17.0+200.0+1.0+5.0-118.0";         system.out.println(engine.eval(exp));     }     } 

output:

119.0