To increment a variable means to add 1 to its value. An index is an expression used to select one of a number of element s of a vector or an array . An index variable is a variable used to hold an . Initialization is the process of setting the initial value of a variable . In particular, you cannot assign a value to a const , but you can, and indeed must, initialize it when it is created.
Input is the process of reading data into the computer from the outside world.
A very commonly used source of input for simple programs is the keyboard. The type bool is sometimes also considered an integer variable type. An istream is a stream used for input. For example, cin is a predefined istream that reads characters from the keyboard.