Loop and Array issue

[oaklander]

I have this JSP where I have alot of fields with conditions.
I would like to make it more efficient and use a for loop.
Here is an example (showing 2 fields for example only):

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
 
    if (!firstname.equals(""))
    {
        errors.put("firstname",firstname);
    }
    if (!lastname.equals(""))
    {
        errors.put("lastname",lastname);
    }
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
%>
 

It prints out Joe Miller

Now my attempt below to put this in a loop prints out null null:

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
//String[] keys = {"firstname", "lastname"};
String[] keys = {firstname, lastname};
for(int i = 0;i < keys.length;i++)
{
     if(!keys[i].equals(""))
    {
        errors.put(keys[i],keys[i]);
    }
}
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
 
%>
 

Please advise.

[nickyeng]

Hi there,

try this

for(int i = 0;i < keys.length;i++)
      {
 
          if(!keys[i].equals(""))
 
          {
 
              errors.put(keys[i],keys[i]);
           out.println(errors.get(keys[i]));   // put in the for loop inside.
 
          }
      }
 

it runs well and print the value.

you shouldn't put 'firstname' and 'lastname' in out.print()...

if you put field into array, its the best to do is use array[0] , array[1] and so on.

[JosAH]

You associate "Joe" with "Joe" and "Miller" with "Miller" in your HashMap. You
can't be surprised that the key "firstname" can not be found in that map.

kind regards,

Jos

[misaw]

I have this JSP where I have alot of fields with conditions.
I would like to make it more efficient and use a for loop.
Here is an example (showing 2 fields for example only):

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
 
    if (!firstname.equals(""))
    {
        errors.put("firstname",firstname);
    }
    if (!lastname.equals(""))
    {
        errors.put("lastname",lastname);
    }
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
%>
 

It prints out Joe Miller

Now my attempt below to put this in a loop prints out null null:

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
//String[] keys = {"firstname", "lastname"};
String[] keys = {firstname, lastname};
for(int i = 0;i < keys.length;i++)
{
     if(!keys[i].equals(""))
    {
        errors.put(keys[i],keys[i]);
    }
}
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
 
%>
 

Please advise.

firstname is a string variable containing "Joe" and in loop you actually inserted the key having value "Joe" not the "firstname"

either try this
out.println(errors.get("Joe"));

or
out.println(errors.get(firstname)); i e without double quotes to get the output.

[gaya3]

I have this JSP where I have alot of fields with conditions.
I would like to make it more efficient and use a for loop.
Here is an example (showing 2 fields for example only):

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
 
    if (!firstname.equals(""))
    {
        errors.put("firstname",firstname);
    }
    if (!lastname.equals(""))
    {
        errors.put("lastname",lastname);
    }
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
%>
 

It prints out Joe Miller

Now my attempt below to put this in a loop prints out null null:

<%@ page language="java" import="java.util.*"  %>
<%
HashMap errors = new HashMap();
String firstname = "Joe";
String lastname = "Miller";
//String[] keys = {"firstname", "lastname"};
String[] keys = {firstname, lastname};
for(int i = 0;i < keys.length;i++)
{
     if(!keys[i].equals(""))
    {
        errors.put(keys[i],keys[i]);
    }
}
 
out.println(errors.get("firstname"));
out.println(errors.get("lastname"));
 
%>
 

Please advise.

Hi,
Following code may help u...
import java.util.*;
class InputLines
{
public static void main(String args[])
{
HashMap errormap = new HashMap();
String firstname="joe";
String lastname="miller";
String[] keys ={firstname,lastname};
for(int i=0;i<keys.length;i++)
{
errormap.put(keys[i],keys[i]);
}
System.out.println("firstname:"+errormap.get(first name));
System.out.println("lastname:"+errormap.get(lastna me));

}
}



u have to get like errormap.get(firstname).. wer firstname string value is considered as key in hashmap...


-Thanks,
Hamsa.

[r035198x]

Hi,
Following code may help u...
import java.util.*;
class InputLines
{
public static void main(String args[])
{
HashMap errormap = new HashMap();
String firstname="joe";
String lastname="miller";
String[] keys ={firstname,lastname};
for(int i=0;i<keys.length;i++)
{
errormap.put(keys[i],keys[i]);
}
System.out.println("firstname:"+errormap.get(first name));
System.out.println("lastname:"+errormap.get(lastna me));

}
}



u have to get like errormap.get(firstname).. wer firstname string value is considered as key in hashmap...


-Thanks,
Hamsa.

1.) Please use code tags when posting code
2.) Did you even test this code of yours to see what it does when it's run?