For loop over contacts list is not executing

I am trying to create a contact management program.My plan is to use an arraylist of a class called contact that I have created. After storing the details,I can get the name and number using the get method.The below code is the main code.

import java.util.ArrayList;
import java.util.Scanner;
public class hello {
public static void main(String[] args) {
while (true)
{
System.out.printf("1.Manage contacts \n2.Message \n3.Quit \nSelect an option: ");
Scanner inp=new Scanner(System.in);
ArrayList<Contact> contacts=new ArrayList<Contact>();
int choice=inp.nextInt();
int counter = 0,i;
switch (choice)
{
case 1:
System.out.printf("\n1.Show all contacts \n2.Add a new contact \n3.Search for a contact \n4.Delete a contact \n5.Go back to the previous item \nSelect an option: ");
Scanner inpt=new Scanner(System.in);
int opt=inpt.nextInt();
if (opt==2) {
System.out.printf("Enter the name: ");
Scanner nm=new Scanner(System.in);
String name=nm.next();
System.out.printf("Enter the number: ");
Scanner numb=new Scanner(System.in);
int num=numb.nextInt();
Contact c=new Contact(name,num);
counter++;
System.out.printf("Counter: %d\n",counter);
contacts.add(c);
}
else if (opt==1){
i=0;
for (i=0;i<counter;i++){
//System.out.printf("Inside\n"); This line is to check if the loop is running 
//or not
contacts.get(i).showname();
contacts.get(i).shownum();
}
}
break;
}
}
}
}

The code for contact is below.It has the two methods shownum and showname which should help me display the name and number.

package com.example.attemp1;
public class Contact {
private String name;
private int number;
public Contact(String name,int number){
this.name=name;
this.number=number;
}
public void showname(){
System.out.printf("Name: %s\t",this.name);
}
public void shownum(){
System.out.printf("Number: %d\n",this.number);
}
}

But the problem is that for loop to show the name and number doesn't work.I mean that the loop isn't even executing.

Your arraylist initialization is misplaced, so you are creating a new arraylist every time you receive a new command and any changes would be deleted.

To solve this, place ArrayList<Contact> contacts=new ArrayList<Contact>(); before the while loop.

You also use a counter variable which you should place outside the loop for the same reason, however note that the ArrayList class has a method called size() that you can use to keep track of the number of items, so you don't need it.

You do not need to create a new scanner object every time you want to scan something, you can create it once outside the while loop.

Scanner sc = new Scanner(System.in);

You do not need to create a variable named i at the start of your method (function in c) like the c language, this is the common way to use for loops in java:

                for (int i=0;i<counter;i++){
//System.out.printf("Inside\n"); This line is to check if the loop is running
//or not
contacts.get(i).showname();
contacts.get(i).shownum();
}

You re-initialise your Contacts List and Counter at each iteration of the main loop.
You should move the initialisations before the while(true).

I.E.

   public static void main(String[] args) {
// MOVE INITIALISATION HERE
ArrayList<Contact> contacts=new ArrayList<Contact>();
int counter = 0,i;
while (true)
{
System.out.printf("1.Manage contacts \n2.Message \n3.Quit \nSelect an option: ");
Scanner inp=new Scanner(System.in);
//REMOVE INIT FROM HERE
//ArrayList<Contact> contacts=new ArrayList<Contact>();
int choice=inp.nextInt();
//REMOVE INIT FROM HERE
//int counter = 0,i;

However a less error prone mode is to change the for loop too with

 for( Contact c:contacts)

so you don't have to mantain the counter variable and you can remove it completely

I tried you code and your variables contacts, counter and i is placed inside the while loop which reset in each iteration. you should define those variables above your while loop like below:

public class hello {
public static void main(String[] args) {
int counter = 0,i;
ArrayList<Contact> contacts=new ArrayList<Contact>();
while (true)
{
System.out.printf("1.Manage contacts \n2.Message \n3.Quit \nSelect an option: ");
Scanner inp=new Scanner(System.in);
int choice=inp.nextInt();
switch (choice)
{
case 1:
System.out.printf("\n1.Show all contacts \n2.Add a new contact \n3.Search for a contact \n4.Delete a contact \n5.Go back to the previous item \nSelect an option: ");
Scanner inpt=new Scanner(System.in);
int opt=inpt.nextInt();
if (opt==2) {
System.out.printf("Enter the name: ");
Scanner nm=new Scanner(System.in);
String name=nm.next();
System.out.printf("Enter the number: ");
Scanner numb=new Scanner(System.in);
int num=numb.nextInt();
Contact c=new Contact(name,num);
counter++;
System.out.printf("Counter: %d\n",counter);
contacts.add(c);
}
else if (opt==1){
i=0;
for (i=0;i<counter;i++){
//System.out.printf("Inside\n"); This line is to check if the loop is running 
//or not
contacts.get(i).showname();
contacts.get(i).shownum();
}
}
break;
}
}
}
}

I tested it already it works. Cheers