Name
++ — NN 2 IE J1 ECMA 1
Synopsis
The increment operator. This unary operator adds 1 to the current value of a variable expression. You can place the operator in front of or behind the variable for a different effect. When the operator is in front of the variable, the variable is incremented before it is evaluated in the current statement. For example, in the following sequence:
var a, b a = 5 b = ++a
1 is added to a
before being assigned to
b
. Therefore, both b
and
a
are 6 when these statements finish running. In
contrast, in the following sequence:
var a, b a = 5 b = a--
the addition occurs after a
is assigned to
b
. When these statements complete,
b
is 5 and a
is 6.
This behavior impacts the way for
-loop-counting
variables are defined and used. Typically, a loop counter that counts
upward from a minimum value increments the counter after the
statements in the loop have run. Thus most loop counters place the
operator after the counter variable:
for (var i = 10; i >=0; i++) ...
Example
++n n++
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