How to pass parameters values from one method to another one in the same class

I'm writing this code for an ATM simulator, with deposit, withdrawal and balance inquiry functionality. The code needs to be written with methods and not switch statements.
My deposit method works, but I have issues with both the withdraw and balanceInquiry methods. I would like to have checkAc_bal accessible to all methods, in order to perform calculations. I'm new on Java, and I'm trying to wrap my head on methods behaviors. Thanks so much.

...

import java.util.Scanner;
public class Main
{
public static void showMenu()
{
Scanner sc = new Scanner(System.in) ;
String input = null ;
do
{
input = showOptions(sc) ;
if(input != null)
{
switch(input.trim())
{
case "1" :    deposit(sc) ;
break ;
case "2" :    withdraw(sc);
break ;
case "3" :    balanceInquiry() ;
break ;enter code here
case "4" :    System.exit(0);
default  :  System.out.println("Wrong option entered. Exiting application") ;
System.exit(0);
}
}
}while(true) ;
}
public static String showOptions(Scanner sc)
{
System.out.println("********************Welcome to ATM Machine******************** ");
System.out.println("Enter Option");
System.out.println("1. Deposit");
System.out.println("2. Withdrawal");
System.out.println("3. Balance Inquiry");
System.out.println("4. Exit\n");
String input = sc.nextLine() ;
return input ;
}
public static void deposit (Scanner sc) {
int checkAc_bal = 0;
System.out.print("Enter amount to be deposited:");
int deposit;
Scanner s = new Scanner(System.in);
deposit = s.nextInt();
//int checkAc_bal = 0;
checkAc_bal = checkAc_bal + deposit;
System.out.println("Your Money has been successfully deposited");
System.out.println("Balance: " +checkAc_bal);
}
public static void withdraw (Scanner sc){
System.out.print("Enter money to be withdrawn:");
int withdraw;
Scanner s = new Scanner(System.in);
withdraw = s.nextInt();
if(withdraw<=checkAc_bal)
{
checkAc_bal = checkAc_bal - withdraw;
System.out.println("Please collect your money");
}
else
{
System.out.println("Insufficient Balance");
}
System.out.println("");
}
public static void balanceInquiry () {
System.out.println("Balance: " + checkAc_bal);
}
public static void main(String[] args) {
showMenu();
}
}

If you want your int to be accessible to other methods, you need to declare it in the scope of the whole class and not inside a method. Try declaring checkAc_bal in the Main class.

define it as a class member:

import java.util.Scanner;
public class Main
{
static int checkAc_bal = 0;   //<------------------------add this
public static void showMenu()
{
Scanner sc = new Scanner(System.in) ;
String input = null ;
do
{
input = showOptions(sc) ;
if(input != null)
{
switch(input.trim())
{
case "1" :    deposit(sc) ;
break ;
case "2" :    withdraw(sc);
break ;
case "3" :    balanceInquiry() ;
break ;enter code here
case "4" :    System.exit(0);
default  :  System.out.println("Wrong option entered. Exiting application") ;
System.exit(0);
}
}
}while(true) ;
}
public static String showOptions(Scanner sc)
{
System.out.println("********************Welcome to ATM Machine******************** ");
System.out.println("Enter Option");
System.out.println("1. Deposit");
System.out.println("2. Withdrawal");
System.out.println("3. Balance Inquiry");
System.out.println("4. Exit\n");
String input = sc.nextLine() ;
return input ;
}
public static void deposit (Scanner sc) {
//        int checkAc_bal = 0;  <---------------- remove this 
System.out.print("Enter amount to be deposited:");
int deposit;
Scanner s = new Scanner(System.in);
deposit = s.nextInt();
//int checkAc_bal = 0;
checkAc_bal = checkAc_bal + deposit;
System.out.println("Your Money has been successfully deposited");
System.out.println("Balance: " +checkAc_bal);
}
public static void withdraw (Scanner sc){
System.out.print("Enter money to be withdrawn:");
int withdraw;
Scanner s = new Scanner(System.in);
withdraw = s.nextInt();
if(withdraw<=checkAc_bal)
{
checkAc_bal = checkAc_bal - withdraw;
System.out.println("Please collect your money");
}
else
{
System.out.println("Insufficient Balance");
}
System.out.println("");
}
public static void balanceInquiry () {
System.out.println("Balance: " + checkAc_bal);
}
public static void main(String[] args) {
showMenu();
}
}

You have three queries, here are the answers :

1. Declare the variable globally to be accessible from all the methods.
2. Not to use switch case (U need to use if-else in that case)
3. How to pass parameters to methods in same class ?
   I see you already did this in your code. You called other methods by parameters and received them as well.

Or frame your question well , as what exactly you need.

So here is the complete code :

import java.util.Scanner;
public class Main{
static int checkAc_bal = 0;  // <---- declare on class scope
public static void showMenu()    {
Scanner sc = new Scanner(System.in) ;
String input = null ;
do {
input = showOptions(sc) ;
if(input != null) {
// removed the switch-case and if-else used
if(input.trim().equals("1"))      {deposit();} 
else if(input.trim().equals("2")) {withdraw();}
else if(input.trim().equals("3")) {balanceInquiry();}
else if(input.trim().equals("4")) {System.exit(0);}
else {
System.out.println("Wrong option entered. Exiting application") ;
System.exit(0);
}
}
}while(true) ;
}
public static String showOptions(Scanner sc){
System.out.println("********************Welcome to ATM Machine******************** ");
System.out.println("Enter Option");
System.out.println("1. Deposit");
System.out.println("2. Withdrawal");
System.out.println("3. Balance Inquiry");
System.out.println("4. Exit\n");
String input = sc.nextLine() ;
return input ;
}
public static void deposit () {
System.out.print("Enter amount to be deposited:");
int deposit;
Scanner s = new Scanner(System.in);
deposit = s.nextInt();
checkAc_bal = checkAc_bal + deposit;
System.out.println("Your Money has been successfully deposited");
System.out.println("Balance: " +checkAc_bal);
}
public static void withdraw (){
System.out.print("Enter money to be withdrawn:");
int withdraw;
Scanner s = new Scanner(System.in);
withdraw = s.nextInt();
if(withdraw<=checkAc_bal) {
checkAc_bal = checkAc_bal - withdraw;
System.out.println("Please collect your money");
} else {
System.out.println("Insufficient Balance");
}
System.out.println("");
}
public static void balanceInquiry () {
System.out.println("Balance: " + checkAc_bal);
}
public static void main(String[] args) {
showMenu();
}
}

Output :

********************Welcome to ATM Machine******************** 
Enter Option
1. Deposit
2. Withdrawal
3. Balance Inquiry
4. Exit
1
Input : 1
Enter amount to be deposited:100
Your Money has been successfully deposited
Balance: 100
********************Welcome to ATM Machine******************** 
Enter Option
1. Deposit
2. Withdrawal
3. Balance Inquiry
4. Exit
1
Input : 1
Enter amount to be deposited:200
Your Money has been successfully deposited
Balance: 300
********************Welcome to ATM Machine******************** 
Enter Option
1. Deposit
2. Withdrawal
3. Balance Inquiry
4. Exit
1
Input : 1
Enter amount to be deposited:200
Your Money has been successfully deposited
Balance: 500
********************Welcome to ATM Machine******************** 
Enter Option
1. Deposit
2. Withdrawal
3. Balance Inquiry
4. Exit
3
Input : 3
Balance: 500
********************Welcome to ATM Machine******************** 
Enter Option
1. Deposit
2. Withdrawal
3. Balance Inquiry
4. Exit