Unit 2 Review Guide

User Manual:

Open the PDF directly: View PDF PDF.
Page Count: 4

DownloadUnit-2-review-guide
Open PDF In BrowserView PDF
Javascript Circuit

UNIT 2 REVIEW GUIDE
KEY TERMS & DEFINITIONS
Boolean
A variable that can either equal true or false.
var isEven = true;
Condition
A mathematical statement that evaluates to true or false.
(x > 10)
Operator
A sign that allow us to make comparisons in a condition.
=, <, >
Statement
Code used to perform an action.
return y;
Collection
Groups of values and an array is an example of a collection
Type Coercion
If the values on both sides of the double equals sign (==) have a different type (i.e., the number 1 and the
string "1"), JavaScript will try to change the type of both operands to check whether or not they are equal.
7 == "7" //returns true
Expression
Code that is written whenever a value is expected.
y+6
Logical Operators
Operators used to combine several boolean statements into a single statement (i.e., AND, NOT, OR).
If it is raining AND I have an umbrella, then I will go outside with an umbrella.

Undefined
A variable that is not assigned a value.
var x;
Null
A variable declared to have no value.
var playerScore = null;
Truthy
Something that evaluates to true, like strings, non-zero numbers, or true.
("Hello Dolly") //truthy
Falsey: Something that evaluates to false. This includes false, 0 (zero), " " (empty string), null, undefined,
or NaN (a special Number value meaning Not-a-Number).
("") //falsey
if Statement
Allows us to check whether or not a condition is true and, if it is, runs our code.
else if Statement
Allows us to specify a second condition to test; this second conditions will only be tested if the first
condition evaluates to false.
else Statement
Default action taken if none of the other conditions in a code block are true.
The following code contains examples for the last three definitions:
if (answer === 38) {
// Do something if first condition is true
} else if (answer === 30) {
// Do something if second condition is true
} else {
// Do something if all above conditions are false
}
Loop
A JS command that tells your program to repeat something.

while Loop
A loop that runs a block of code over and over again as long as our condition remains true (or at least
truthy).

while (someCondition) {
// A block of code.
}

for Loop
A loop that runs for a fixed, controllable number of times, ensuring it will never get stuck in an infinite
loop.
for(var i = 0; i < 100; i++) {
//Note: i is not syntax but stands for any variable
//Do something for a 100 times.
}
Switch Statement
A variable that gets evaluated; if there is a case listed for the value that it evaluates to, the code between
case __: and break will be executed.

var grade = "B";
switch (grade) {
case "A":
console.log("Awesome Job");
break;
case "B":
console.log("Good Job");
break;
case "V":
console.log("Okay Job");
break;
case "D":
console.log("Bad Job");
break;
case "F":
console.log("Horrible Job");
break;
default:
console.log("Nonexistent");
}
Ternary Statement
The one-line shorthand for an if...else statement.
var goToWork = day === "Saturday" || day === "Sunday" ? false : true;
Truth Table
A table for determining whether something will evaluate to true or false.

A

B A AND B A OR B NOT A

false false false

false

true

false true false

true

true

true false false

true

false

true true true

true

false

_____________________________________________________________________

GUIDING QUESTIONS
1.
2.
3.
4.
5.
6.
7.

How does an if/else statement control the logic of your program?
What is the difference between == and ===?
How does boolean logic manipulate conditionals?
What is a for loop?
What is a while loop?
Why would we use a switch statement?
What is a ternary statement?

________

LOGICAL OPERATORS AND COMMANDS
Command Description
<

Less than

>

Greater than

<=

Less than or equal to

>=

Greater than or equal to

===

Strict equal to

==

Equal to

!==

Strict not equal to

!=

Not equal to

||

OR

&&

AND

!

NOT

break;

Exit function (necessary in switch statements)

null

Used to declar variable to have no value
Source Exif Data: 
File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.4
Linearized                      : No
Title                           : 
Creator                         : wkhtmltopdf 0.12.3
Producer                        : Qt 4.8.7
Create Date                     : 2016:08:10 18:05:00Z
Page Count                      : 4
Page Mode                       : UseOutlines
EXIF Metadata provided by EXIF.tools

Navigation menu