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javascriptc#postfix-operator

Execution of postfix ++ operation

How does a postfix ++ operator works :

var a = 100;
var b = a++ + a;
//Result 201

Here if 'a' is incremented then should not the value be 202. And if it is true then should not be the next equation value 301 ?

var a = 100;
var b = a++ + a + a;
//Result 302
Solution

  • In 

    var a = 100;
var b = a++ + a;

    what happens is:

    1. a is set to 100
    2. a++ is evaluated. The value of that subexpression is 100. Also, a is set to 101.
    3. The value of a (101) is added to the value of the left-hand subexpression (100).
    4. b is set to the result, 201.

    The postfix ++ operator returns the value of the variable as it was before the increment. The prefix ++ operator (as in ++a) performs the increment and gives the value after that.

    The behavior in JavaScript is the same as in many other languages with expression syntax and semantics derived from C.