Practice Quiz on Objects

In this first question, you're going to create an object.

First, create a variable called "animals". Then, assign it an object with two properties: "type" and "color". Then assign two values to those properties, the first value for type should be the string "Horse", and the second for color should be the string "brown".

var animals = { "type":"Horse", "color": "brown" };

Create an object variable called "chicken" with three properties: name, age and wingsclipped. Assign the string "Clucker" for the name, the number 2 for age, and a boolean true for wingsclipped.

var chicken = { "name":"Clucker", "age":2, "wingsclipped":true };

Create an object variable called "pets" with two properties: names and colors. The values for both names and colors should be an array of three values. For names use strings Fido, Spot, and Buttercup. For colors use strings black, brown, and purple.

var pets = {
   "names"  : ["Fido", "Spot", "Buttercup"],
   "colors" : ["black", "brown", "purple"]
};

Create an object variable called "school" with two properties: schoolname and concentrations. For name assign the string "UCB J-School", and for concentrations assign an array with string values: reporting, writing, and coding.

var school = {
   "schoolname"     : "UCB J-School",
   "concentrations" : ["reporting", "writing", "coding"]
};

Create an array (not an object) variable called "myDogs" and store three objects in it. Each object should have two properties: name and age. Store the following data: Rex who is 1, Fido who is 14, and Princess who is 5.

var myDogs = [
   { "name":"Rex",      "age":1 },
   { "name":"Fido",     "age":14 },
   { "name":"Princess", "age":5 }
];

Create an array called "crimes" and store three objects in it. Each object should have three properties: weapon, homicide, and location. The data types for these properties should be string, boolean, and an array of two numbers (lat and lon).

Store the following data:
1. A gun was used that resulted in a homicide at 40.452107, 93.742118.
2. A knife was used that resulted in a homicide at 52.479748, 62.185657.
3. A gun was used that did not result in a homicide at 19.646162, 37.295270.

var crimes = [
   { "weapon":"gun",   "homicide":true, "location": [40.452107, 93.742118] },
   { "weapon":"knife", "homicide":true, "location": [52.479748, 62.185657] },
   { "weapon":"gun",   "homicide":false, "location": [19.646162, 37.295270] }
];

Type out the dot notation for retrieving the dog's color.

var dog = {
   "name": "Bruno",
   "type": "bulldog",
   "fixed": true,
   "color": "black"
};

dog.color

Now, type out the square-bracket notation for retrieving the dog's color.

var dog = {
   "name": "Bruno",
   "type": "bulldog",
   "fixed": true,
   "color": "black"
};

dog["color"]

Use square-bracket notation for retrieving the type of cat.

var cat = {
   "name"        : "Smelly",
   "type of cat" : "Tabby",
   "gender"      : "male"
};

cat["type of cat"]

Use dot notation for retrieving the name of the second cat:

var the_cat = [
   {"name":"Jonesy", "color":"gray"},
   {"name":"Smarty", "color":"purple"},
   {"name":"Spot",   "color":"white"}
];

the_cat[1].name

Now use square-bracket notation for retrieving the name of the second cat:

var the_cat = [
   {"name":"Jonesy", "color":"gray"},
   {"name":"Smarty", "color":"purple"},
   {"name":"Spot",   "color":"white"}
];

the_cat[1]["name"]

Use dot notation for retrieving the latitude of the third shooting (hint, latitude generally comes first in location data):

var shootingsData = [
   { "weapon" : "gun", "homicide" : false, "location":[40.452107, 93.742118], "order": 1 },
   { "weapon" : "knife", "homicide" : true, "location":[52.479748, 62.185657], "order": 2 },
   { "weapon" : "vehicle", "homicide" : true, "location":[19.646162, 37.295270], "order": 3 }
];

shootingData[2].location[0]

Now use square-bracket notation for retrieving the latitude of the third shooting (hint, latitude generally comes first in location data):

var shootingsData = [
   { "weapon" : "gun", "homicide" : false, "location":[40.452107, 93.742118], "order": 1 },
   { "weapon" : "knife", "homicide" : true, "location":[52.479748, 62.185657], "order": 2 },
   { "weapon" : "vehicle", "homicide" : true, "location":[19.646162, 37.295270], "order": 3 }
];

shootingData[2]["location"][0]

Type three separate lines of square-bracket notation to retrieve the URLs for each photo:

var photos = [
   {"title":"matter", "url":"http://placehold.it/300x300"},
   {"title":"kittens", "url":"http://placekitten.com/300/300/"},
   {"title":"Charlie", "url":"http://placesheen.com/300/300/"}
];

photos[0]["url"]
photos[1]["url"]
photos[2]["url"]

Visit this URL showing a JSON file from Kickstarter, which displays recent projects with the term "Berkeley". You can copy-and-paste this into a code editor and format the code. Specify the dot notation for the "name" of the third project.

projects[2].name

Using the same url from the previous question, type the dot notation for "little" photo of the fifth project.

projects[4].photo.little

Using the same url, type the dot notation for thumbnail of the creator's avatar of the first project.

projects[0].creator.avatar.thumb