Strings if you wish to store a quote inside a string

Strings
• If you wish to store a quote inside a string of text than you have a few options:
• Option 01:
• Alternate your quote types between double and single quotes
• const someString = ‘The man said “Hello”’;
• This will not work with the second example string:
• const anotherString = ‘I’m the person that said “Hello”;
• This will fail because the apostrophe in “I’m” will cause the initial opening single
quote to close after the letter “I”
• Use option 02 or option 03 for strings which contain various quotes and apostrophes
• Option 02:
• Use the “ \ ” escape character to escape the next character in the string
• Using the “ \ ” escape character tells JavaScript to ignore any special meaning that the next
character may have
• const yetAnotherString = ‘I\’m the person that said “Hello”’;
• Option 03:
• Use Template Strings (more on template strings in upcoming slides). Template strings use back
ticks ( `` ) to store strings
• const aString = `I’m the person that said “Hello”`;

Strings
• Concatenating string values
• To concatenate string values means to combine two or
more strings together to form a single larger string
• To combine strings together you use the “+”
let a = ‘Hello’ ;
let b = ‘World’ ;
alert ( a + ‘ ’ + b );
This empty string adds a space
between the two words

Template Strings
• Another type of string which is new to JavaScript is a template string
• Template strings are formed by wrapping text in backticks ( `` )
• Template strings allow for variables to be placed directly inside the
string by using the ${variableName} syntax
• Below is an example of a template screen that has a variable inside
the string
const output = `The country is ${ country }` ;
• Expressions can also be resolved inside template strings
• Below is an example of an expression being resolved inside a template string
const sum = `12 + 6 = ${ 12 + 6 }` ;

Numbers
• A number is pretty much just what it says, it is a number
• The following are numbers
• 2
• 0
• -3
• 0.23589
• -0.12
• 6.82
• -8.276
• Unlike other computer languages integers (whole numbers) and
floating point (numbers with decimals points) do not have special or
separate data types

Arithmetic Operators
Operator Description Example Value of Quantity
= assign quantity = 10 10
+ addition quantity = 10 + 6 16
- subtraction quantity = 10 - 6 4
* multiplication quantity = 10 * 2 20
/ division quantity = 10 / 2 5
66

Booleans
• Variables that have a data type of a Boolean can only
store the values of true or false
• Often used in conditional statements
• Example:
let x = true;
if (x == true){
// do something
};

Strings that Look Like Numbers
• Often in JavaScript we are retrieving data from our users via a form
• When data is returned from a form to JavaScript the data is always in
the form of a string
• For example if the user enters their age in a form then submits the form the
data that is returned is "43" (or whatever age they entered). Notice the
quotes around the number. This number looks like a number but is actually a
string
• The problems arise when we try to perform some math functions on the
number using the "+" operator. If we try to add the number to 2 to the string
number "43" we would get "432" and not 45 as JavaScript thinks "43" is a
string so concatenates 2 on to the end of the string