Re: Array reference in for loop

From:
 Daniel Pitts <googlegroupie@coloraura.com>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 14 Aug 2007 13:21:09 -0700
Message-ID:
<1187122869.529135.73820@m37g2000prh.googlegroups.com>
On Aug 14, 9:15 am, Patricia Shanahan <p...@acm.org> wrote:

IchBin wrote:

tes...@hotmail.com wrote:

I have a validate method in a bean class that works and now I want to
condense it into a for loop.

Here is what I have:

 //firstname and lastname are declared earlier
 public boolean validate()
 {
    boolean allOk=true;
    if (firstName.equals("")) {
      errors.put("firstName","Please enter your first name");
      allOk=false;
    }
    if (lastName.equals("")) {
      errors.put("lastName","Please enter your last name");
      allOk=false;
    }
    return allOk;
  }

My attempt doesnt work because I cant seem to figure out how to put
the array reference in the key part of the errors.put method:

 public boolean validate()
 {
    boolean allOk=true;
    String [] myarray = {firstname, lastname}
    for(int i=0;i < myarray.length;i++)
    {
    if (myarray[i].equals("")) {
      errors.put(myarray[i],"Please enter your " + myarray[i]);
      allOk=false;
    }
    }
    return allOk;
  }

The results dont validate any of my data so I assume I have something
wrong with my array. Please advise.


Quick and dirty:

    public boolean validate()
    {
        boolean allOk=true;
        String [] myarray = {firstName, lastName,
                            "first Name","last Name"};
        for(int i=0;i < myarray.length;i++){
            if (myarray[i].equals("")) {
                errors.put(myarray[i] + " Please enter your " +
                                          myarray[i+2]);
                allOk=false;
            }
        }
        return allOk;
    }


There are two needs for a String array, providing the labels for using
in the message and holding the input. Why not use two arrays, one for
each job?

     public boolean validate()
     {
         boolean allOk=true;
         String[] input = {firstName, lastName};
         String[] labels = {"first Name","last Name"};
         for(int i=0;i < input.length;i++){
             if (input[i].equals("")) {
                 errors.put(input[i] + " Please enter your " +
                                           labels[i]);
                 allOk=false;
             }
         }
         return allOk;
     }

I don't like names like "myarray", because they are often associated
with constructs that do not have a single clear purpose.

Patricia


I don't like parallel arrays myself, and I don't think this is a job
for an array actually.

public void validateHelper(String fieldName, String fieldValue, String
message) {
   if (fieldValue == null || fieldValue.equals("")) {
       errors.put(fieldName, fieldMessage);
   }
}

public void validate() {
   validateHelper("firstName", firstName, "Please enter your first
name.");
   validateHelper("lastName", lastName, "Please enter your last
name.");
}

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