freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-an.../basic-javascript/compound-assignment-with-au...

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---
id: 56533eb9ac21ba0edf2244af
title: Compound Assignment With Augmented Addition
challengeType: 1
videoUrl: 'https://scrimba.com/c/cDR6LCb'
forumTopicId: 16661
dashedName: compound-assignment-with-augmented-addition
---
# --description--
In programming, it is common to use assignments to modify the contents of a variable. Remember that everything to the right of the equals sign is evaluated first, so we can say:
```js
myVar = myVar + 5;
```
to add `5` to `myVar`. Since this is such a common pattern, there are operators which do both a mathematical operation and assignment in one step.
One such operator is the `+=` operator.
```js
let myVar = 1;
myVar += 5;
console.log(myVar);
```
`6` would be displayed in the console.
# --instructions--
Convert the assignments for `a`, `b`, and `c` to use the `+=` operator.
# --hints--
`a` should equal `15`.
```js
assert(a === 15);
```
`b` should equal `26`.
```js
assert(b === 26);
```
`c` should equal `19`.
```js
assert(c === 19);
```
You should use the `+=` operator for each variable.
```js
assert(code.match(/\+=/g).length === 3);
```
You should not modify the code above the specified comment.
```js
assert(
/let a = 3;/.test(code) &&
/let b = 17;/.test(code) &&
/let c = 12;/.test(code)
);
```
# --seed--
## --after-user-code--
```js
(function(a,b,c){ return "a = " + a + ", b = " + b + ", c = " + c; })(a,b,c);
```
## --seed-contents--
```js
let a = 3;
let b = 17;
let c = 12;
// Only change code below this line
a = a + 12;
b = 9 + b;
c = c + 7;
```
# --solutions--
```js
let a = 3;
let b = 17;
let c = 12;
a += 12;
b += 9;
c += 7;
```