Randell Dawson e9212c61d2 fix(curriculum): Remove unnecessary assert message argument from English challenges JavaScript Algorithms and Data Structures - 01 (#36401)
* fix: rm assert msg basic-javascript

* fix: removed more assert msg args

* fix: fixed verbiage

Co-Authored-By: Parth Parth <34807532+thecodingaviator@users.noreply.github.com>
2019-07-13 08:07:53 +01:00

99 lines
2.3 KiB
Markdown

---
id: 56533eb9ac21ba0edf2244c7
title: Accessing Object Properties with Dot Notation
challengeType: 1
videoUrl: 'https://scrimba.com/c/cGryJs8'
---
## Description
<section id='description'>
There are two ways to access the properties of an object: dot notation (<code>.</code>) and bracket notation (<code>[]</code>), similar to an array.
Dot notation is what you use when you know the name of the property you're trying to access ahead of time.
Here is a sample of using dot notation (<code>.</code>) to read an object's property:
```js
var myObj = {
prop1: "val1",
prop2: "val2"
};
var prop1val = myObj.prop1; // val1
var prop2val = myObj.prop2; // val2
```
</section>
## Instructions
<section id='instructions'>
Read in the property values of <code>testObj</code> using dot notation. Set the variable <code>hatValue</code> equal to the object's property <code>hat</code> and set the variable <code>shirtValue</code> equal to the object's property <code>shirt</code>.
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: <code>hatValue</code> should be a string
testString: assert(typeof hatValue === 'string' );
- text: The value of <code>hatValue</code> should be <code>"ballcap"</code>
testString: assert(hatValue === 'ballcap' );
- text: <code>shirtValue</code> should be a string
testString: assert(typeof shirtValue === 'string' );
- text: The value of <code>shirtValue</code> should be <code>"jersey"</code>
testString: assert(shirtValue === 'jersey' );
- text: You should use dot notation twice
testString: assert(code.match(/testObj\.\w+/g).length > 1);
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
// Setup
var testObj = {
"hat": "ballcap",
"shirt": "jersey",
"shoes": "cleats"
};
// Only change code below this line
var hatValue = testObj; // Change this line
var shirtValue = testObj; // Change this line
```
</div>
### After Test
<div id='js-teardown'>
```js
(function(a,b) { return "hatValue = '" + a + "', shirtValue = '" + b + "'"; })(hatValue,shirtValue);
```
</div>
</section>
## Solution
<section id='solution'>
```js
var testObj = {
"hat": "ballcap",
"shirt": "jersey",
"shoes": "cleats"
};
var hatValue = testObj.hat;
var shirtValue = testObj.shirt;
```
</section>