Günay's Coding World

These 2 loops are the same. subscriber_user_ids = [] #first loop for user_record in [2,3,4,5]:     subscriber_user_ids.append(user_record)     print(user_record) #second loop    str1 = ','.join(str(user_record) for user_record in [2,3,4,5]) print(str1) https://repl.it/repls/AstonishingInconsequentialRhombus

ArrayList  and  Vector  both implements List interface and maintains insertion order.But there are many differences between  ArrayList  and  Vector  classes... ArrayList  - ArrayList  is not synchronized. ArrayList  increments 50% of current array size if number of element exceeds from its capacity. ArrayList  is not a legacy class, it is introduced in JDK 1.2. ArrayList  is fast because it is non-synchronized. ArrayList  uses Iterator interface to traverse the elements. Vector  - Vector  is synchronized. Vector  increments 100% means doubles the array size if total number of element exceeds than its capacity. Vector  is a legacy class. Vector  is slow because it is synchronized i.e. in multithreading environment, it will hold the other threads in runnable or non-runnable state until current thread releases the lock of object. Vector  uses Enumeration interface to traver...

No nonsense, four ways to loop ArrayList in Java For loop For loop (Advance) While loop Iterator loop package com.mkyong.core ;   import java.util.ArrayList ; import java.util.Iterator ; import java.util.List ;   public class ArrayListLoopingExample { public static void main ( String [ ] args ) {   List < String > list = new ArrayList < String > ( ) ; list. add ( "Text 1" ) ; list. add ( "Text 2" ) ; list. add ( "Text 3" ) ;   System . out . println ( "#1 normal for loop" ) ; for ( int i = 0 ; i < list. size ( ) ; i ++ ) { System . out . println ( list. get ( i ) ) ; }   System . out . println ( "#2 advance for loop" ) ; for ( String temp : list ) { System . out . println ( temp ) ; }   System . out . println ( "#3 while loop" ) ; int j = 0 ; while ( list. size ( ) > j ) { System . out . println ( list. get ( j ...