java - how to initialize a destructive variable? -

this question has answer here:

• how compare strings in java? 23 answers

hi want ask how initialize variable when you're gonna use in condition? here's code made far..

import java.io.*;  public class bwiset{     public static void main(string[]args){         bufferedreader br=new bufferedreader(new inputstreamreader(system.in));         int t=0;         double v=0;           string vt,tt;         double tc;  try{          system.out.print("==================================\nvehicle type \tcharge per km \n car \t\t php0.50\n light truck \t php0.75");         system.out.print("\n bus \t\t php1.00");         system.out.print("\n heavy truck \t php1.25\n");         system.out.print("==================================\n");         system.out.print("km travelled \t ticket color\n");         system.out.print("   15 \t \t yellow\n");         system.out.print("   25 \t \t blue\n");         system.out.print("   50 \t \t red\n");         system.out.print("   75 \t \t orange\n");             system.out.println("welcome! please enter vehicle type: ");         vt=br.readline();         system.out.println("enter ticket type: ");         tt=br.readline();              if (vt=="car"||vt=="car"||vt=="car"||vt=="car"||vt=="car"||vt=="car"||vt=="car"){             v=0.50;         }else if (vt=="light truck"||vt=="light truck"||vt=="light truck"){             v=0.75;         }else if (vt=="bus"||vt=="bus"||vt=="bus"){             v=1.00;         }else if (vt=="heavy truck"||vt=="heavy truck"||vt=="heavy truck"){             v=1.25;         }            if (tt=="yellow"||tt=="yellow"||tt=="yellow"){             t=15;         }else if (tt=="blue"||tt=="blue"||tt=="blue"){             t=25;         }else if (tt=="red"||tt=="red"||tt=="red"){             t=50;         }else if (tt=="orange"||tt=="orange"||tt=="orange"){             t=75;         }             tc=v*t;            system.out.println("vehicle type: " + vt);         system.out.println("ticket type:" + tt);         system.out.println("charge according vehicle: " + v);         system.out.println("kilometers traveled according ticket: " + t);         system.out.print("total toll charge: " + tc);    }catch(ioexception e){ }      } } 

to make short, program runs when input vehicle type , ticket type, still returns 0 isn't supposed happen-- because used conditions assigns value each vehicle type , ticket types (also shown in table comes program). i've tried search proper initializations related can't find , confused. please help. sorry bein such noob

don't use == compare string values; in java, objects, == compares object references determine if refer same object.

use string#equals compare string values.

if (vt.equals("car") || vt.equals("car")) 

in fact, string#equalsignorecase better in case, cut down on number of conditions in each if statement:

if (vt.equalsignorecase("car"))