# How to JavaScript Part 1

*How to Comment: *

*How to Comment:*

In JavaScript you can store a variable with the assignment operator:

myVariable = 5;

Assigns the Number value 5 to myVariable.

Assigns the Number value 5 to myVariable.

*Initializing Variable with the Assignment Operator*

It is common to initialize a variable to an initial value in the same line as it is declared.

It is common to initialize a variable to an initial value in the same line as it is declared.

var myVar =0;

or

var a = 9;

meaning a = 9

or

var a = 9;

meaning a = 9

*Understanding Uninitialized Variables*

**
**

When Javascript declares variables, they have an initial value of undefined. Undefined mathamatical operations result in "NaN" or "Not a number" Here is an example of taking undefined variables to defined.

Before:

* Initialize these three variables*

var a;

var b;

var c;

Do not change code below this line

a = a + 1;

b = b + 5;

c = c + " String!";

After:

* Initialize these three variables*

var a = 5;

var b = 10;

var c = "I am a"

Do not change code below this line

a = a + 1;

b = b + 5;

c = c + " String!";

#####

*camelCaseing***
**

JavaScript is case sensitive and (Oh crap I probably made a million empty pages on the wiki doing this...) and is really important.

*Adding/ Subtracting/Multipling and Dividing Numbers*

Number is a data type in **JavaScript which represents numeric data. Use + to add two numbers together (duh?)**

Add:

myVar = 5 + 10; * assigned 15*

Subtract:

var difference = 45 - 33;

Multiply:

myVar = 13 * 13; assigned 169

Subtract:

myVar = 16 / 2; * assigned 8*

*
*

*
*Increment a Number (add one to a number )**
**

When Javascript declares variables, they have an initial value of undefined. Undefined mathamatical operations result in "NaN" or "Not a number" Here is an example of taking undefined variables to defined.

Before:

*Initialize these three variables*

var a;

var b;

var c;

Do not change code below this line

var a;

var b;

var c;

a = a + 1;

b = b + 5;

c = c + " String!";

After:

*Initialize these three variables*

var a = 5;

var b = 10;

var c = "I am a"

Do not change code below this line

var a = 5;

var b = 10;

var c = "I am a"

a = a + 1;

b = b + 5;

c = c + " String!";

JavaScript is case sensitive and (Oh crap I probably made a million empty pages on the wiki doing this...) and is really important.

JavaScript is case sensitive and (Oh crap I probably made a million empty pages on the wiki doing this...) and is really important.

*Adding/ Subtracting/Multipling and Dividing Numbers*

Number is a data type in

Number is a data type in

**JavaScript which represents numeric data. Use + to add two numbers together (duh?)**

Add:

myVar = 5 + 10;

Subtract:

myVar = 16 / 2;

Add:

myVar = 5 + 10;

*assigned 15*

Subtract:

var difference = 45 - 33;

Multiply:

myVar = 13 * 13;assigned 169Subtract:

var difference = 45 - 33;

Multiply:

myVar = 13 * 13;

Subtract:

myVar = 16 / 2;

*assigned 8*

**Finding a Remainder in JavaScript**###

###
#####
The remainder operator % gives the remainder of the division of two numbers.

Example

5 % 2 = 1 because

Math.floor(5 / 2) = 2 (Quotient)

2 * 2 = 4

5 - 4 = 1 (Remainder)

Usage

In mathematics, a number can be checked even or odd by checking the remainder of the division of the number by 2.

17 % 2 = 1 (17 is Odd)

48 % 2 = 0 (48 is Even)

Note

The remainder operator is sometimes incorrectly referred to as the "modulus" operator. It is very similar to modulus, but does not work properly with negative numbers.

var remainder = 11 % 3;

* Only change code below this line*

var remainder;

*
*

*
Compound Assignment With Augmented Addition
*

The remainder operator % gives the remainder of the division of two numbers.

Example

5 % 2 = 1 because

Math.floor(5 / 2) = 2 (Quotient)

2 * 2 = 4

5 - 4 = 1 (Remainder)

Usage

In mathematics, a number can be checked even or odd by checking the remainder of the division of the number by 2.

17 % 2 = 1 (17 is Odd)

48 % 2 = 0 (48 is Even)

Note

The remainder operator is sometimes incorrectly referred to as the "modulus" operator. It is very similar to modulus, but does not work properly with negative numbers.

*Only change code below this line*

var remainder;

var remainder;

*Compound Assignment With Augmented Subtraction*###

Compound Assignment With Augmented Multiplication###