Chapter 4 Flashcards
Data and Variables
A specific piece of data, such as a word or a number.
Value
A value category
Data type
Numeric Value
Number
Sequences of characters enclosed in quotes
String
Code segments that are reduced to a value (typeof “Hello, World!”)
Expression
What does an Expression do?
What does (typeof “Hello, World”) do?
Returns a value
Returns the value String.
A set of rules that determine how the languages deal with data of different types
Type System
When number and string functions will convert their arguments into types number and string, respectively.
Type Conversion
(Number(“1234”));
Represents a number not as a number
NaN - Special Value
A name that refers to a value. A container
Variable
The act of creating a variable
Declaration
The act of assigning a variable for the first time
Initialization
‘let’ not ‘var’
To give a variable a value
Assignment statement
To give a variable a value, using ‘=’
Assignment Operator
When we refer to a variable name
Evaluating
An unchangeable variable
Constant
‘const’
Words reserved by JavaScript for use by the language.
Keywords
Variable names or phrases that are joined together, start with a lower case letter, then capitalize each internal word.
Camel case
A combination of values, variables, operators, and calls to functions.
Expression
The evaluation of an expression produces a value
Return value
One or more characters that represent a computation like addition, multiplication, or division
Operator
The values the operator works on
Operand
Joining two strings
Concatenate
+ in between strings
Shorthand Operators
Compound Assignment Operators
What is the shorthand for:
a = a + b
a += b
What is the shorthand for:
a = a - b
a -= b
What is the shorthand for:
a = a * b
a *= b
What is the shorthand for:
a = a / b
a /= b
