Basic Terminology

To further understand how the Scanner class works, we must first understand how the input is handled.

To do this, we learn about the concept of an input token, a delimiter, and an input stream.

• A delimiter is any character or sequence of distinct characters that separates the input string into smaller portions of characters called tokens.

  For example, if we have the following input:

  and we set our delimiter as " ", then these smaller strings divided by the delimiter are what we call tokens.

• Likewise, a token is any sequence of characters from the input separated by a delimiter.
  As an example, if we have the delimiter ",", and the following input:

  Therefore, we can separate the input into two tokens, as displayed by the following:

• A stream is any set of tokens arranged in a sequence.
  For example in an input string: abc 123 true 3.14, the first token in the stream is abc, the second token in the stream is 123, and so on.

Using delimiters and tokens, we can have a good idea of how Scanner works.