63 lines
1.5 KiB
Markdown
63 lines
1.5 KiB
Markdown
|
---
|
||
|
|
id: 587d7b88367417b2b2512b46
|
||
|
|
title: Set Default Parameters for Your Functions
|
||
|
|
challengeType: 1
|
||
|
|
forumTopicId: 301209
|
||
|
|
dashedName: set-default-parameters-for-your-functions
|
||
|
|
---
|
||
|
|
|
||
|
|
# --description--
|
||
|
|
|
||
|
|
In order to help us create more flexible functions, ES6 introduces <dfn>default parameters</dfn> for functions.
|
||
|
|
|
||
|
|
Check out this code:
|
||
|
|
|
||
|
|
```js
|
||
|
|
const greeting = (name = "Anonymous") => "Hello " + name;
|
||
|
|
|
||
|
|
console.log(greeting("John")); // Hello John
|
||
|
|
console.log(greeting()); // Hello Anonymous
|
||
|
|
```
|
||
|
|
|
||
|
|
The default parameter kicks in when the argument is not specified (it is undefined). As you can see in the example above, the parameter `name` will receive its default value `"Anonymous"` when you do not provide a value for the parameter. You can add default values for as many parameters as you want.
|
||
|
|
|
||
|
|
# --instructions--
|
||
|
|
|
||
|
|
Modify the function `increment` by adding default parameters so that it will add 1 to `number` if `value` is not specified.
|
||
|
|
|
||
|
|
# --hints--
|
||
|
|
|
||
|
|
The result of `increment(5, 2)` should be `7`.
|
||
|
|
|
||
|
|
```js
|
||
|
|
assert(increment(5, 2) === 7);
|
||
|
|
```
|
||
|
|
|
||
|
|
The result of `increment(5)` should be `6`.
|
||
|
|
|
||
|
|
```js
|
||
|
|
assert(increment(5) === 6);
|
||
|
|
```
|
||
|
|
|
||
|
|
A default parameter value of `1` should be used for `value`.
|
||
|
|
|
||
|
|
```js
|
||
|
|
assert(code.match(/value\s*=\s*1/g));
|
||
|
|
```
|
||
|
|
|
||
|
|
# --seed--
|
||
|
|
|
||
|
|
## --seed-contents--
|
||
|
|
|
||
|
|
```js
|
||
|
|
// Only change code below this line
|
||
|
|
const increment = (number, value) => number + value;
|
||
|
|
// Only change code above this line
|
||
|
|
```
|
||
|
|
|
||
|
|
# --solutions--
|
||
|
|
|
||
|
|
```js
|
||
|
|
const increment = (number, value = 1) => number + value;
|
||
|
|
```
|