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); }
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]); } }
You are confusing the name of the variable with the value of the variable. <%@ page language="java" import="java.util.*" %> <% HashMap errors = new HashMap(); String firstname = "Joe"; String lastname = "Miller"; String[] keys = {"firstname", "lastname"}; String[] values = {firstname, lastname}; for(int i = 0;i < keys.length;i++) { if(!keys[i].equals("")) { errors.put(keys[i],values[i]); } }
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