JavaScript 2.0-The Complete Reference, Second ... - freecodingtutorial

y = y - 1
is fine. But if you make it
x = x + 1 y = y - 1
you will throw an error. Also, if you break a statement up into multiple lines you might cause a
problem. The classic example is the return statement. Because the argument to return is
optional, placing return and its argument on separate lines causes the return to execute
without the argument. For example,
return
x
is treated as
return;
x;
rather than what was probably intended:
return x;
For this reason and others, such as readability of your code, terminating statements with a line
break and relying on implicit semicolon insertion is not only poor programming style, but a bad
idea and should be avoided.
Blocks
Curly braces ({ }) are used to group a series of consecutive statements together. Doing so
creates one large statement, so a block of statements enclosed in curly braces can be used
anywhere in JavaScript that a single statement could. For example, a statement is expected as
the body of an if conditional:
if (some condition)
do something;
Because a block is treated as a single statement, you could also write
if (some condition)
{
}
do something;
do something else;
...