Statements
A compilation unit contains a set of executable statements. In web browsers, each
<script> tag delivers a compilation
unit that is compiled and immediately executed. Lacking a linker, JavaScript throws
them all together in a common global namespace. There is more on global variables in
Appendix A.
When used inside of a function, the var
statement defines the function's private variables.
The switch, while, for, and do statements are allowed to have an optional
label prefix that interacts with the break statement.
Statements tend to be executed in order from top to bottom. The sequence of
execution can be altered by the conditional statements (if and switch), by the looping
statements (while, for, and do), by the disruptive
statements (break, return, and throw), and by
function invocation.
A block is a set of statements wrapped in curly braces. Unlike many other languages, blocks in JavaScript do not create a new scope, so variables should be defined at the top of the function, not in blocks.
The if statement changes the flow of the program based on the value of the expression. The ...
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