Loop exercices from #30daysofjavascript with VanillaJS

https://github.com/Asabeneh/30-Days-Of-JavaScript/blob/master/06_Day_Loops/06_day_loops.md

Learning

• constraint number of iterations with for(i=0; i<=array.length; i++)
• reverse iteration with for(i=countries.length-1; i>=0 ; i--)
• repeat() string method associated with for(i) to add a pattern
• condition inside the for loop
• pushing random numbers in array
• generate a random 6 characters ID