1. Variables
Kevin Harville

2. Variables
Variables are a named space in the computer where a value is stored.
Examples
User’s age
User’s name
Any characters or numbers you need use in which the values may vary.

3. Variable Names Names are CASE SENSITIVE
Var totalStudents is not TotalStudents
Use letters or underscore. Can use numbers after the first character
var Student_Name;
var Score7;
Be descriptive. Use no punctuation or spaces.
var NumberOfFishInGrandmasAquarium;

4. Variable Scope
The “scope” of a variable is the range within the program where it can be used.
If a variable is declared within a function, the scope of the variable is local, meaning limited to that function.
Other variables are global to the entire script.

5. Data Types
Variables in JavaScript are variant. That means that they are usually not specified as being a particular type of data, such as characters, a decimal number, or a number.
However, we can specify our data as being of a particular type if needed.

6. Data Types Numbers Boolean ( true / false ) Strings (characters)
Null values (JavaScript keyword null)

7. Converting Strings to Numbers
Any input from the user may be considered by the computer to be strings of characters.
“10” + “40” = “1040”
Therefore we tell the computer to consider the text to be integer or floating point (decimal numbers).
age = parseInt(age);
myFraction = parseFloat(myInput);

8. Just Remember…
If your input should be an integer convert it using parseInt().
If your input should be a decimal convert it using parseFloat().
If your response is NaN, then the computer can’t convert it to a number