What is the difference between the add/decrement operator before or after a variable?

Question

An example would be:

i++ vs ++i
or
--i vs i--

Answer 1

Post increment and pre increment.
var i = 2;
document.write(i++);
The output of this code is 2. Why?
This way of incrementing uses the value of i and then increments it.
The opposite of this would be this:
var i = 2;
document.write(++i);
The output of this code would be 3, because this way will increment the value and then use it.
Hope this helps!

Answer 2

A simple example:

public class NewMain {

public static void main(String[] args) {

int i = 0;
while (i < 3) {
System.out.println(++i + ". line");
}

System.out.println();

i = 0;
while (i < 3) {
System.out.println(i++ + ". line");
}
}
}

-----------
Output:
1. line
2. line
3. line

0. line
1. line
2. line

Answer 3

they are called prefix and postfix variables....
a++ = prefix
++a = postfix
both will give you the same results because in both cases the a is being incremented but it is important when we use a second veriable..
---------------------------
like
a=10;
c = a++;
and after that if i do
printf("%d %d",c,a);
then the..
c will have 10 and
a will be 11
because 1st it assigns the variable into c then it increments the a
------------------------
like
a=10;
c = ++a;
and after that if i do
printf("%d %d",c,a);
then the..
c will have 11 and
a will be 11

Answer 4

pre increment adds 1 before operation
post increment adds 1 after operation
pre decrement subtracts 1 before operation
post decrement subtracts 1 after operation

Answer 5

operator before a variable means change-then-use value i.e. it changes the value of the variable first then uses it whereas in operator after a variable use-then-change is being implemented..For eg. suppose i=5; then for
{++i
cout<<i;
}
Here output would be 6

whereas for
{i++;
cout<<i;
}
Here output would be 5
Similarly,
{--i;
cout<<i;
}
would show output 4

and;

{i--;
cout<<i;
}
would show output 5 which is assigned value.

Answer 6

There are two types of operators in both add/decrement prefix(++x) and postfix(x++). In prefix increase the value before using. In postfix first use the value then increase. In decrement the decrease value