Your 'edit' method should be:
public static Integer edit(String [] list, Integer listSize){
Scanner userInput = new Scanner(System.in);
System.out.print("Enter the row number of the item you would like to edit: ");
try{
Integer row = userInput.nextInt();
if(row <= 0){
System.out.println("ERROR: The number can't be negative or zero!");
}
//check if int is too large
else if(row > listSize-1){
System.out.println("ERROR: The number is too big for the list.");
}
else{
/*
for(int i=row; i<listSize; i++){
list[i] = list[i+1];
}
*/
}
System.out.print("Enter name of item: ");
String name = userInput.nextLine();
System.out.print("Enter number of items: ");
String number = userInput.nextLine();
//list[listSize] = name + ", " + number;
list[row] = name + ", " + number;
}
catch(InputMismatchException exception){
System.out.println("ERROR: You must enter a number to edit an item.");
}
return listSize ;
}