Loops plays an important feature when repeated task like executing an expression 50 times, example checking prime numbers between 2 to 50. There are three types, for loop when the start and end is fixed also known as entry controlled loop. Next is while loop which, unlike for loop is more flexible and execute a set of statements, behaviour is entry controlled condition, finaly a loop that execute once whatever the condition is, the do while loop is useful in many ways and it checks the condition during exit hence, it is like test before continue scenarios. Note, usually beginners miss that semicolon after while condition.