I'm trying to write a method in java to run cases of a user-entered string.

The code:

 static String checkWMI(String userVIN){

    String manCountry = null;
    String WMI = userVIN.substring(0, 5);
    String Wcheck = WMI.substring(WMI.length()- 4);

    if(Wcheck.equals("1") || Wcheck.equals("4") || Wcheck.equals("5")) {
         manCountry = "United States";
    }else if(Wcheck.equals("J")){
        manCountry = "Japan";
    }else if(Wcheck.equals("2")){
        manCountry = "Canada";
    }else if(Wcheck.equals("3")){
        manCountry = "Mexico";
    }else if(Wcheck.equals("S")){
        manCountry = "United Kingdom";
    }else if(Wcheck.equals("W")) {
        manCountry = "Germany";
    }

    return manCountry;
}
 }

The goal is to get a specific sub-string (so I can print it out later) and then determine a value based on a piece of that substring. I want to decide this based on the character indexed at zero. When I try to run this code, only "null" prints because it says my "if statement is always false". I know there must be a logic error somewhere, but I can't find it. Any suggestions?

CodePudding user response：

static String checkWMI(String userVIN){

String manCountry = null;
String WMI = userVIN.substring(0, 5);

if(WMI.startsWith("1") || WMI.startsWith("4")  || WMI.startsWith("5") ) {
     manCountry = "United States";
}else if(Wcheck.equals("J")){
    manCountry = "Japan";
}else if(Wcheck.equals("2")){
    manCountry = "Canada";
}else if(Wcheck.equals("3")){
    manCountry = "Mexico";
}else if(Wcheck.equals("S")){
    manCountry = "United Kingdom";
}else if(Wcheck.equals("W")) {
    manCountry = "Germany";
}

return manCountry;

} }

or

static String checkWMI(String userVIN){

String manCountry = null;
String WMI = userVIN.substring(0, 5);

if(WMI.charAt(0) == "1" || WMI.charAt(0) == "4"  || WMI.charAt(0) == "5"  ) {
     manCountry = "United States";
}else if(Wcheck.equals("J")){
    manCountry = "Japan";
}else if(Wcheck.equals("2")){
    manCountry = "Canada";
}else if(Wcheck.equals("3")){
    manCountry = "Mexico";
}else if(Wcheck.equals("S")){
    manCountry = "United Kingdom";
}else if(Wcheck.equals("W")) {
    manCountry = "Germany";
}

return manCountry;

} }