Increment a Number with JavaScript ++

Increment a Number with JavaScript ++


Tell us what’s happening:

The test of changing the code is not running (only that one). and obviously i’ve changed it!

Your code so far

myVar = ++myVar ;

var myVar = 87;

// Only change code below this line
myVar = ++myVar ;

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.77 Safari/537.36.

Link to the challenge:


Read the instructions again carefully. Look at the example code and read the “Note”.



your syntax is incorrect. Try reading the note in the exercise again.


Technically your code should pass all of the tests given what they say explicitly. Say you have a variable like so:

var a = 0;
a === 1; //true

it is the same as:

var a = 0;
a = a + 1;
a === 1; //true

what you did was:

var a = 0;
a = ++a;
a === 1; //true

++a evaluates to a + 1 so assigning a = ++a; will do the same thing as a++; or ++a.
if you instead do a = a++ a will be assigned the current value of a (or NaN if a is not a number) and the increment won’t happen.

The point of this challenge is to teach you the shorthand of incrementing a number by one like this though:

// a is now 1 more than before

This syntax is very useful and used in many programming languages.


Thanks guys! I understand it now