he setTimeout() method calls a function or evaluates an expression after a specified number of milliseconds. ... If you need to repeat execution, use the setInterval() method. Tip: Use the clearTimeout() method to prevent the function from running. static means there is only one copy of the variable in memory shared by all instances of the class. The final keyword just means the value can't be changed. Without final , any object can change the value of the variable. The static keyword implies class-level scope. When you combine static final in Java, you create a variable that is global to the class and impossible to change. In object-oriented programming (OOP), an instance is a concrete occurrence of any object, existing usually during the runtime of a computer program. ... Each realized variation of that object is an instance of its class. An array is a collection of elements of a similar data type. A linked list is a collection of objects known as a node where node consists of two parts, i.e., data and address. Array elements store in a contiguous memory location. Linked list elements can be stored anywhere in the memory or randomly stored.