if statement - How to check and Entry before adding and store it in an Array in Java? -
good day.. have address book program... runs doesn't check if user input stored in array.. want want is... after getting user input compare stored entry in array , when unique... allow user add new entry...
here's old code in addentry():
public void addentry() {
entry[counter] = new addressbookentry(); entry[counter].setname(joptionpane.showinputdialog("enter name: ")); entry[counter].setadd(joptionpane.showinputdialog("enter add: ")); entry[counter].setphoneno(joptionpane.showinputdialog("enter phone no.: ")); entry[counter].setemail(joptionpane.showinputdialog("enter e-mail: ")); counter++; }
and here's planning turns out error:
public void addentry() {
entry[counter] = new addressbookentry(); sname = joptionpane.showinputdialog("enter name: ");//<-- asks user name if (!entry[counter].getname().equals(sname)) {//<--compare entry[counter].setname(joptionpane.showinputdialog("enter name: ")); entry[counter].setadd(joptionpane.showinputdialog("enter add: ")); entry[counter].setphoneno(joptionpane.showinputdialog("enter phone no.: ")); entry[counter].setemail(joptionpane.showinputdialog("enter e-mail: ")); counter++; } } this error: exception in thread "main" java.lang.nullpointerexception @ addressbook.addentry(addressbook.java:57) @ addressbook.main(addressbook.java:28) java result: 1 build successful (total time: 4 seconds)
the output ask user input name , exit automatically... might logical error... don't know possible solution
need please thanks
here's complete code:
import javax.swing.joptionpane; import javax.swing.jtextarea; public class addressbook { private addressbookentry entry[]; private int counter; private string sname; private int notfound = 0; public static void main(string[] args) { addressbook = new addressbook(); a.entry = new addressbookentry[100]; int option = 0; try { while (option != 5) { string content = "choose option\n\n" + "[1] add entry\n" + "[2] delete entry\n" + "[3] update entry\n" + "[4] view entries\n" + "[5] view specific entry\n" + "[6] exit"; option = integer.parseint(joptionpane.showinputdialog(content)); switch (option) { case 1: a.addentry(); break; case 2: a.deleteentry(); break; case 3: a.editentry(); break; case 4: a.viewall(); break; case 5: a.searchentry(); break; case 6: system.exit(1); break; default: joptionpane.showmessagedialog(null, "invalid choice!"); } } } catch (numberformatexception e) { joptionpane.showmessagedialog(null, "please choose number in displayed menu"); } } public void addentry() { entry[counter] = new addressbookentry(); sname = joptionpane.showinputdialog("enter name: "); if (entry[counter] == null && entry[counter].getname() == null && !entry[counter].getname().equals(sname)) { entry[counter].setname(joptionpane.showinputdialog("enter name: ")); entry[counter].setadd(joptionpane.showinputdialog("enter add: ")); entry[counter].setphoneno(joptionpane.showinputdialog("enter phone no.: ")); entry[counter].setemail(joptionpane.showinputdialog("enter e-mail: ")); counter++; } } /*public void addentry() { entry[counter] = new addressbookentry(); entry[counter].setname(joptionpane.showinputdialog("enter name: ")); entry[counter].setadd(joptionpane.showinputdialog("enter add: ")); entry[counter].setphoneno(joptionpane.showinputdialog("enter phone no.: ")); entry[counter].setemail(joptionpane.showinputdialog("enter e-mail: ")); counter++; }*/ public void viewall() { string addtext = " name\taddress\tphone no.\te-mail add\n\n"; int nonnull = 0; (int = 0; < entry.length; i++) { if (entry[i] != null) { addtext = addtext + entry[i].getinfo() + "\n"; nonnull++; } if (nonnull == counter) { break; } } joptionpane.showmessagedialog(null, new jtextarea(addtext)); } public void searchentry() { sname = joptionpane.showinputdialog("enter name find: "); searchmethod(); } public void searchmethod() { (int = 0; < counter; i++) { if (entry[i].getname().equals(sname)) { joptionpane.showmessagedialog(null, entry[i].getinfo2()); notfound = 0; break; } else { notfound++; } } if (notfound != 0) { joptionpane.showmessagedialog(null, "name not found!"); } } public void editentry() { sname = joptionpane.showinputdialog("enter name edit: "); (int = 0; < counter; i++) { if (entry[i].getname().equals(sname)) { entry[i] = new addressbookentry(); entry[i].setname(joptionpane.showinputdialog("enter new name: ")); entry[i].setadd(joptionpane.showinputdialog("enter new add: ")); entry[i].setphoneno(joptionpane.showinputdialog("enter new phone no.: ")); entry[i].setemail(joptionpane.showinputdialog("enter new e-mail: ")); notfound = 0; break; } else { notfound++; } } if (notfound != 0) { joptionpane.showmessagedialog(null, "name not found!"); } } public void deleteentry() { sname = joptionpane.showinputdialog("enter name delete: "); if (sname == null) { return; } (int = 0; < counter; i++) { if (entry[i] != null && sname.equals(entry[i].getname())) { entry[i] = null; joptionpane.showmessagedialog(null, "found!"); break; } } } } hope can me... because still dont understand do. show complete code... patience guys...
check make sure entry isn't null before try doing getname() it.
if (!entry[counter].getname().equals(sname)) turns into:
if (entry[counter] != null && entry[counter].getname() != null && !entry[counter].getname().equals(sname))
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