2.1 Variable Discovery
variables store and manage data
to declare a variable
var variableName = 3
naming variables no spaces, no digits at the front, camelCase is good
reuse assignment operator to assign a new value but you dont need to use var again because the variable is already created or inside memory
all operations can be used with assignments such as *=
2.4 Variable Exploration
variables can store numbers and strings
you can use methods like .length on variables that store strings
strings are indexed from 0
.charAt() method