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javajls

Can't understand the definition of a Java statement

I think I understand this part: "Some statements contain other statements as part of their structure; such other statements are substatements of the statement."

Source: (second paragraph) http://docs.oracle.com/javase/specs/jls/se8/html/jls-14.html

Please correct me if I'm wrong: This refers to method calls, which contain multiple statements within. This also refers to actions such as performing some kind of operation like calculating or concatting a String while initializing.

What I'm having troubles understand is this: "We say that statement S immediately contains statement U if there is no statement T different from S and U such that S contains T and T contains U"

I'm not gonna lie, they totally lost me here. I can't imagine this in my head, or write it out on paper. The wording has me totally confused.

Can someone please explain this is an easier to understand fashion?

Solution

  • If you have for example 

    if (Expression1)
  while (Expression2)
    Statement1

    then the IfThenStatement immediately contains a WhileStatement. It also contains Statement1, but it does not immediately contain Statement1.

    Referring to the symbols used in the JLS spec S is the IfThenStatement which contains the WhileStatement T, which in turn contains Statement1 U. Therefore S does not immediately contain U.