javascript variables and data types. output without alert or form console.log();

JavaScriptVARIABLES AND DATA TYPES

OUTPUT WITHOUT ALERT OR FORM

CONSOLE.LOG();

Holding information

example

A = B + C;

Cubby Hole 2: add this value

Cubby Hole 1: take this value

Cubby Hole 3: place it here

Defining CUBBY HOLESThey are called variables

Define them Give them values Take values from them

= means “takes the value of”A takes the value of B+C

VALUES

What values can it take?

Any “expression” What is an expression?

Variables Constants Operators functions

Different for numbers and strings

Numbers

Regular math operators Variables Constants Functions (random, floor)

Strings

Think of Scrabble tiles Each tile is a

Letter Number Punctuation mark Space (blank)

What is a String?A literal string must be inside

double quotes or single quotes“this is a string” and this is not a

string.Remember to beware cut and paste

Concatenating (formally) It means combining two or more

things into one thing + Anything can be concatenated

“awe” & “some” = “awesome” Whitespace only matters inside quotes

“a”+“b” same as “a” = “b” “a ” + “b” NOT the same as “a” + “b”

SubstringA substring is also a StringA substring is a part of another

string“cake” is a substring of “birthday cake”so are “day”, “thd”, and “y cake”“they” is not, neither is “hello” or

“dude” Will come back to how to extract

substrings

Referencing characters Each character has a position

Note that it starts at 0, not 1

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